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Product listing: Acetyl-Histone H3 (Lys27) (D5E4) XP® Rabbit mAb (PE Conjugate), UniProt ID P68431 #15562 to Lipin 1 (D2W9G) Rabbit mAb, UniProt ID Q14693 #14906

$364
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to phycoerythrin (PE) and tested in-house for direct flow cytometry analysis in human cells. This antibody is expected to exhibit the same species cross-reactivity as the unconjugated Acetyl-Histone H3 (Lys27) (D5E4) XP® Rabbit mAb #8173.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Flow Cytometry

Background: The nucleosome, made up of four core histone proteins (H2A, H2B, H3, and H4), is the primary building block of chromatin. Originally thought to function as a static scaffold for DNA packaging, histones have now been shown to be dynamic proteins, undergoing multiple types of post-translational modifications, including acetylation, phosphorylation, methylation, and ubiquitination (1,2). Histone acetylation occurs mainly on the amino-terminal tail domains of histones H2A (Lys5), H2B (Lys5, 12, 15, and 20), H3 (Lys9, 14, 18, 23, 27, 36 and 56), and H4 (Lys5, 8, 12, and 16) and is important for the regulation of histone deposition, transcriptional activation, DNA replication, recombination, and DNA repair (1-3). Hyper-acetylation of the histone tails neutralizes the positive charge of these domains and is believed to weaken histone-DNA and nucleosome-nucleosome interactions, thereby destabilizing chromatin structure and increasing the accessibility of DNA to various DNA-binding proteins (4,5). In addition, acetylation of specific lysine residues creates docking sites for a protein module called the bromodomain, which binds to acetylated lysine residues (6). Many transcription and chromatin regulatory proteins contain bromodomains and may be recruited to gene promoters, in part, through binding of acetylated histone tails. Histone acetylation is mediated by histone acetyltransferases (HATs), such as CBP/p300, GCN5L2, PCAF, and Tip60, which are recruited to genes by DNA-bound protein factors to facilitate transcriptional activation (3). Deacetylation, which is mediated by histone deacetylases (HDAC and sirtuin proteins), reverses the effects of acetylation and generally facilitates transcriptional repression (7,8).

The Aurora Antibody Sampler Kit provides an economical means to investigate the G2/M phase of the cell cycle. The kit contains enough primary and secondary antibodies to perform two western blots with each antibody.

Background: Aurora kinases belong to a highly conserved family of mitotic serine/threonine kinases with three members identified among mammals: Aurora A, B, and C (1,2). Studies on the temporal expression pattern and subcellular localization of Aurora kinases in mitotic cells suggest an association with mitotic structure. Aurora kinase functional influences span from G2 phase to cytokinesis and may be involved in key cell cycle events such as centrosome duplication, chromosome bi-orientation and segregation, cleavage furrow positioning, and ingression (3). Aurora A is detected at the centrosomes, along mitotic spindle microtubules, and in the cytoplasm of mitotically proliferating cells. Aurora A protein levels are low during G1 and S phases and peak during the G2/M phase of the cell cycle. Phosphorylation of Aurora A at Thr288 in its catalytic domain increases kinase activity. Aurora A is involved in centrosome separation, maturation, and spindle assembly and stability. Expression of Aurora B protein also peaks during the G2/M phase of the cell cycle; Aurora B kinase activity peaks at the transition from metaphase to the end of mitosis. Aurora B associates with chromosomes during prophase prior to relocalizing to the spindle at anaphase. Aurora B regulates chromosome segregation through the control of microtubule-kinetochore attachment and cytokinesis. Expression of both Aurora A and Aurora B during the G2/M phase transition is tightly coordinated with histone H3 phosphorylation (4,5); research investigators have observed overexpression of these kinases in a variety of human cancers (2,4). Aurora C localizes to the centrosome from anaphase to cytokinesis and both mRNA and protein levels peak during G2/M phase. Although typical Aurora C expression is limited to the testis, research studies report overexpression of Aurora C is detected in various cancer cell lines (6).

$348
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 647 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Nanog (D73G4) XP® Rabbit mAb #4903.
APPLICATIONS
REACTIVITY
Human

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

Background: Nanog is a homeodomain-containing transcription factor that is essential for the maintenance of pluripotency and self renewal in embryonic stem cells (1). Nanog expression is controlled by a network of factors including Sox2 and the key pluripotency regulator Oct-4 (1). Recent advances in somatic cell reprogramming have utilized viral expression of combinations of transcription factors including nanog, Oct-4, Sox2, KLF4, c-Myc, and LIN28 (2,3).

$303
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Immunoprecipitation, Western Blotting

Background: Interleukin-1β (IL-1β), one of the major caspase-1 targets, is a multifunctional cytokine that is involved in a host of immune and proinflammatory responses (1). It is produced primarily by activated monocytes and macrophages. It signals through various adaptor proteins and kinases that lead to activation of numerous downstream targets (2-6). Human IL-1β is synthesized as a 31 kDa precursor. To gain activity, the precursor must be cleaved by caspase-1 between Asp116 and Ala117 to yield a 17 kDa mature form (7,8). Detection of the 17 kDa mature form of IL-1β is a good indicator of caspase-1 activity.

The γ Secretase Antibody Sampler Kit provides an economical means of evaluating components of the gamma secretase complex. The kit contains enough primary and secondary antibodies to perform two western miniblot experiments.
$305
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to phycoerythrin (PE) and tested in-house for direct flow cytometry analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated Bak (D4E4) Rabbit mAb #12105.
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Flow Cytometry

Background: Bak is a proapoptotic member of the Bcl-2 family (1). This protein is located on the outer membrane of mitochondria and is an essential component for transduction of apoptotic signals through the mitochondrial pathway (2,3). Upon apoptotic stimulation, an upstream stimulator like truncated BID (tBID) induces conformational changes in Bak to form oligomer channels in the mitochondrial membrane for cytochrome c release. The release of cytochrome c to the cytosol activates the caspase-9 pathway and eventually leads to cell death (4,5).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse

Application Methods: Western Blotting

Background: Two related serine/threonine kinases, UNC-51-like kinase 1 and 2 (ULK1, ULK2), were discovered as mammalian homologs of the C. elegans gene UNC-51 in which mutants exhibited abnormal axonal extension and growth (1-4). Both proteins are widely expressed and contain an amino-terminal kinase domain followed by a central proline/serine rich domain and a highly conserved carboxy-terminal domain. The roles of ULK1 and ULK2 in axon growth have been linked to studies showing that the kinases are localized to neuronal growth cones and are involved in endocytosis of critical growth factors, such as NGF (5). Yeast two-hybrid studies found ULK1/2 associated with modulators of the endocytic pathway, SynGAP and syntenin (6). Structural similarity of ULK1/2 has also been recognized with the yeast autophagy protein Atg1/Apg1 (7). Knockdown experiments using siRNA demonstrated that ULK1 is essential for autophagy (8), a catabolic process for the degradation of bulk cytoplasmic contents (9,10). It appears that Atg1/ULK1 can act as a convergence point for multiple signals that control autophagy (11), and can bind to several autophagy-related (Atg) proteins, regulating phosphorylation states and protein trafficking (12-16).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: MKK3 and MKK6 are two closely related dual-specificity protein kinases that activate p38 MAP kinase (1-5). MKK3 and MKK6 both phosphorylate and activate p38 MAP kinase at its activation site, Thr-Gly-Tyr, but do not phosphorylate or activate Erk1/2 or SAPK/JNK. Phosphorylation of p38 MAP kinase dramatically stimulates its ability to phosphorylate protein substrates such as ATF-2 and Elk-1. MKK3 and MKK6 are both activated by different forms of cellular stress and inflammatory cytokines (4,5). Activation of MKK3 and MKK6 occurs through phosphorylation at Ser189 and Thr222 on MKK3 (2) and Ser207 and Thr211 on MKK6 (4,5).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Circadian rhythms govern many key physiological processes that fluctuate with a period of approximately 24 hours. These processes include the sleep-wake cycle, glucose, lipid and drug metabolism, heart rate, hormone secretion, renal blood flow, and body temperature, as well as basic cellular processes such as DNA repair and the timing of the cell division cycle (1,2). The mammalian circadian system consists of many individual tissue-specific clocks (peripheral clocks) that are controlled by a master circadian pacemaker residing in the suprachiasmatic nuclei (SCN) of the brain (1,2). The periodic circadian rhythm is prominently manifested by the light-dark cycle, which is sensed by the visual system and processed by the SCN. The SCN processes the light-dark information and synchronizes peripheral clocks through neural and humoral output signals (1,2).The cellular circadian clockwork consists of interwoven positive and negative regulatory loops, or limbs (1,2). The positive limb includes the CLOCK and BMAL1 proteins, two basic helix-loop-helix-PAS containing transcription factors that bind E box enhancer elements and activate transcription of their target genes. CLOCK is a histone acetyltransferase (HAT) protein, which acetylates both histone H3 and H4 (3). BMAL1 binds to CLOCK and enhances its HAT activity (3). The CLOCK/BMAL1 dimer exhibits a periodic oscillation in both nuclear/cytoplasmic localization and protein levels, both of which are regulated by phosphorylation (4,5). CLOCK/BMAL1 target genes include the Cry and Per genes, whose proteins form the negative limb of the circadian clockwork system (1,2). CRY and PER proteins (CRY1, CRY2, PER1, PER2 and PER3) form oligomers that also periodically shuttle between the nucleus and cytoplasm. When in the nucleus, CRY/PER proteins inhibit CLOCK/BMAL1-mediated transcriptional activation, thus completing the circadian transcriptional loop (1,2). In tissues, roughly six to eight percent of all genes exhibit a circadian expression pattern (1,2). This 24-hour periodicity in gene expression results from coordination of the positive and negative regulatory limbs of the cellular clockwork system, and is fine-tuned by outside signals received from the SCN.

$305
50 tests
100 µl
This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 647 fluorescent dye and tested in-house for direct flow cytometry and immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated p21 Waf1/Cip1 (12D1) Rabbit mAb #2947.
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry)

Background: The tumor suppressor protein p21 Waf1/Cip1 acts as an inhibitor of cell cycle progression. It functions in stoichiometric relationships forming heterotrimeric complexes with cyclins and cyclin-dependent kinases. In association with CDK2 complexes, it serves to inhibit kinase activity and block progression through G1/S (1). However, p21 may also enhance assembly and activity in complexes of CDK4 or CDK6 and cyclin D (2). The carboxy-terminal region of p21 is sufficient to bind and inhibit PCNA, a subunit of DNA polymerase, and may coordinate DNA replication with cell cycle progression (3). Upon UV damage or during cell cycle stages when cdc2/cyclin B or CDK2/cyclin A are active, p53 is phosphorylated and upregulates p21 transcription via a p53-responsive element (4). Protein levels of p21 are downregulated through ubiquitination and proteasomal degradation (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

Background: Synoviolin-1 (SYVN1/HRD1) is a RING-type E3 ubiquitin-protein ligase and major component of the endoplasmic reticulum (ER) quality control system that is involved in the ubiquitin-dependent degradation of misfolded proteins (1). SYVN1 is a multispanning ER membrane protein whose expression is upregulated at the protein level under conditions that promote ER stress (1-4). Research studies have shown that SYVN1 is an anti-apoptotic factor that is implicated in the pathogenesis of arthropathy by promoting synovial hyperplasia (5). Furthermore, gene-targeting studies have demonstrated that SYVN1 expression is indispensable for embryogenesis (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: Grp75, also known as mortalin, is a member of Hsp70 family of chaperone proteins that is not heat-inducible (1,2). This protein is essential for transporting many mitochondrial proteins from the cytoplasm to mitochondria (3). Grp75 inactivates the tumor suppressor p53 (4). Studies found that Grp75 is overexpressed in many tumor tissues and immortalized human cell lines, suggesting its role in the tumor formation (5). Grp75 is also implicated in cell aging, as its overexpression appears to prolong the life span of human fibroblasts (6).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Inositol 1,4,5-triphosphate receptor, also known as IP3R or InsP3R, is a member of the intracellular calcium release channel family and is located in the endoplasmic reticulum. IP3R functions as a Ca2+ release channel for intracellular stores of calcium ions. There are three types of IP3 receptors (IP3R1, 2, and 3) that require the second messenger inositol 1,4,5-triphosphate (IP3) for activation (1). Four individual subunits homo- or hetero-oligomerize to form the receptor's functional channel (2). Phosphorylation of IP3R1 at Ser1756 by cyclic AMP-dependent protein kinase A (PKA) regulates the sensitivity of IP3R1 to IP3 and may be a mode of regulation for Ca2+ release (3,4). IP3R1-mediated Ca2+ release appears to have an effect on the induction of long term depression (LTD) in Purkinje cells (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Rat

Application Methods: Western Blotting

Background: Sodium/glucose cotransporter 1 (SGLT1) is an active glucose transporter, which utilizes sodium gradients to transport glucose into cells independent of extracellular glucose concentration. SGLT1 is an essential glucose active transport protein that helps maintain high intracellular glucose levels (1). Expression of SGLT1 is mainly seen in intestinal and kidney epithelial cells, although a recent study also characterized SGLT1 expression in cardiac myocytes (2). Abnormal SGLT1 expression may be associated with cases of type 2 diabetes mellitus and myocardial ischaemia (2). Mutation of the corresponding SGLT1 gene can result in congenital glucose/galactose malabsorption, which can lead to neonatal diarrhea and subsequent death if left untreated (3). A recent study of the role of EGFR in cancer cell survival indicates that EGFR can prevent autophagic cell death independent of EGFR kinase activity because the receptor interacts with and stabilizes SLGT1 to maintain basal intracellular glucose levels (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry), Western Blotting

Background: The sequence-specific transcription factor activator protein 2α (AP-2α) is required for normal growth and morphogenesis during mammalian development (1,2). Decreased or loss of AP-2α expression has been observed in many different types of human cancers including breast cancer (3,4), ovarian cancer (5), melanoma (6) and prostate cancer (7). These findings suggest that AP-2α expression plays a crucial role in tumorigenicity. Studies have also shown that p53 overexpression in human breast carcinoma cells induces the level of AP-2α expression. Furthermore, p53 binds to the cis-element in the AP-2α promoter, suggesting that AP-2α is a target of p53. AP-2α may mediate the effect of p53 to inhibit cell proliferation (8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

Background: The cohesin complex consists of a heterodimer between SMC1 (SMC1A or B) and SMC3, bound by additional RAD21 and STAG proteins (STAG1, 2, or 3) (1,2). These proteins form a ring-like structure that mediates the cohesion of two sister chromatids after DNA replication in S phase (1,2). RAD21 and STAG2 are phosphorylated by Polo-like kinase (PLK) during prophase, which leads to the dissociation of cohesin complexes from the chromosome arms; however, cohesin remains bound to centromeres until anaphase (3,4). RAD21 is cleaved by separin/ESPL1 in anaphase, which leads to dissociation of the remaining cohesin from centromeres, enabling sister chromatids to segregate during mitosis (5). RAD21 is also cleaved by caspase-3 and caspase-7 during apoptosis, resulting in a 64 kDa carboxy-terminal cleavage product that translocates to the cytoplasm and may help to trigger apoptosis (6,7). In addition to mediating cohesion of sister chromatids, the cohesin complex plays important roles in gene regulation and DNA repair, as SMC1 and SMC3 are both phosphorylated by ATM and ATR kinases upon DNA damage (1,2).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Protein phosphatase 2A (PP2A) is a trimeric protein phosphatase and tumor suppressor that regulates the phosphorylation status of a wide variety of phosphoproteins. PP2A targets include many that play a role in the maintenance and progression of cancer (1). The cancerous inhibitor of protein phosphatase 2A (CIP2A) is a single pass membrane protein that binds the PP2A catalytic subunit to inhibit PP2A phosphatase activity (2). CIP2A is normally expressed at low levels in normal cells and tissues, but is elevated in human malignancies where it is thought to be oncogenic. Research studies demonstrate aberrant CIP2A expression in multiple tumor types, including those derived from the head and neck, liver, colon, lung, osteosarcoma, pancreatic, breast, and myeloid cancers (reviewed in 3). This evidence suggests that CIP2A interacts with many proteins that may play a role in cancer maintenance and progression (3). Additional studies indicate that CIP2A inhibits PP2A-mediated dephosphorylation of the proto-oncogene Myc at Ser64, which stabilizes and prevents proteolytic degradation of the Myc transcription factor (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunohistochemistry (Paraffin)

Background: The stromal cell derived factor 1 (SDF1/CXCL12) is a small, pro-inflammatory chemoattractant cytokine that regulates leukocyte trafficking through interactions with its cognate 7-transmembrane G protein-coupled receptors (1). The SDF1/CXCL12 receptor, CXCR4, also serves as a coreceptor for the entry of human immunodeficiency virus into target cells (2). SDF1/CXCL12 may regulate homing and maintenance of CXCR4-expressing stem or progenitor cells, including embryonic and many somatic stem cells (3,4). Many cancer cells express CXCR4, suggesting that SDF1/CXCL12 plays a role in cancer metastasis (5,6). Alternative splicing and differential processing during maturation produce a pair of SDF1/CXCL12 isoforms (SDF1/CXCL12α and SDF1/CXCL12β) that have different properties and biological activities (7). Additional isoforms of SDF1/CXCL12 have been reported (8,9).

$260
100 µl
APPLICATIONS
REACTIVITY
Hamster, Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: Mixed lineage kinase 3 (MLK3) is a serine/threonine kinase that has an amino-terminal SH3 domain followed by the kinase domain and two leucine zippers, a cdc42/Rac1 binding (CRIB) domain and several other domains/motifs at the carboxy-terminal region. CRIB triggers the dimerization of MLK3 via its tandem leucine zippers, followed by the intramolecular phosphorylation and subsequent activation of MLK3 (1,2). Autophosphorylation of Thr277 and Ser281 is essential for MLK3 kinase activity (3). Ser281 is also phosphorylated by HPK in an in vitro kinase assay (3). MLK3 functions as a MAPKKK of the SAPK/JNK stress pathway by directly phosphorylating SEK1/MKK4 and MKK7, although it is controversial whether MLK3 is involved in p38 stress pathway activation (1,4). MLK3 also functions as an IκB kinase and mediates the activation of the transcriptional factor NF-κB stimulated by CD3/CD28, suggesting a role for MLK3 in immune and inflammatory responses (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Chromatin IP, Western Blotting

Background: Histones are evolutionarily conserved proteins that play a vital role in the compaction, storage, and regulation of DNA within the eukaryotic nucleus. The basic subunit of chromatin, the nucleosome core particle, is composed of DNA wound around two copies each of the core histone proteins H2A, H2B, H3, and H4 (1-3). Formation of higher order chromatin structure is facilitated through the binding of linker histone H1 to the nucleosome particle (chromatosome) (4-6). In humans and mice, there are 11 distinct histone H1 variants, which include the somatic variants (H1.1, H1.2, H1.3, H1.4, and H1.5) that are expressed ubiquitously, and cell type specific variants such as H1t found in the testis and H1.0 expressed in terminally differentiated cells (6-10). Binding of histone H1 to chromatin limits accessibility of DNA to other proteins by stabilizing nucleosome positioning, competing for binding sites, and limiting the activity of chromatin remodeling proteins such as the SWI/SNF complex (6,11-14). Histone H1 binding is highly dynamic and is thought to be regulated by post-translational modifications (6). For example, cell cycle regulated phosphorylation of histone H1 leads to chromatin condensation and decondensation depending on the site of phosphorylation and histone H1.4 Lys34 acetylation by GCN5 has been linked to increased mobility of H1.4 and transcriptional activation (6, 15-18).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Mammalian cells synthesize serine de novo by diverting a portion of the glycolytic intermediate 3-phosphoglycerate into the phosphorylated pathway of serine synthesis. This shift supports anabolism by providing precursors for the biosynthesis of proteins, nucleotides, creatine, porphyrins, phospholipids, and glutathione. Phosphoglycerate dehydrogenase (PHGDH) catalyzes the first step in the serine biosynthesis pathway by converting 3-phosphoglycerate into phosphohydroxy pyruvate (1).Research studies demonstrate that an increase in serine biosynthesis supports growth and proliferation of cancer cells (2-4), which is supported by amplification and overexpression of PHGDH in a subset of melanoma and breast cancers (5,6). Suppression of PHGDH expression in cell lines with elevated PHGDH levels causes a strong decrease in cell proliferation and inhibits tumor growth in vivo (5). Additional evidence suggests that PHGDH interacts with and stabilizes FoxM1, which promotes the proliferation, invasion, and tumorigenicity of glioma cells (7).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: HSPB8 (HSP22) is a member of the small heat shock protein superfamily and the human protein is most closely related to HSP27. Similar to most other small HSPs (sHSPs), HSPB8 is predominantly transcribed in skeletal muscle and heart (1). In a two hybrid screen, HSPB8 interacted preferentially with a triple aspartate form of HSP27 which mimics HSP27 phosphorylated at Ser15, Ser78, and Ser82, as compared to wild-type HSP27 (2). HSPB8 has two binding domains (N- and C-terminal) that are specific for different binding partners, and has the ability to bind to itself and other sHSPs such as HSPB7 and HSPB2 (3). The chaperone-like activity is of great importance to the function of HSP22 in various processes including proliferation, apoptosis and macroautophagy (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Activation-induced cytidine deaminase (AID) is thought to modify RNA due to its high homology to the RNA editing enzyme APOBEC-1. This function, however, has not been confirmed in in vitro studies, which show that AID has significant cytidine deaminase activity, and that this activity is blocked by zinc chelation (1).The B cell immune system must specifically recognize several infectious agents, which vastly outnumber immunoglobulin gene segments present in a given organism. Mechanisms such as somatic hypermutation, isotype switch recombination and gene conversion introduce diversity and specificity to the immune system. Analysis of mouse models and patients with AID deficiency has established a link between all three of these mechanisms and AID function (2). AID protein is detected in germinal center centroblast and germinal center derived lymphomas (Burkitt lymphoma), but not in pre-germinal center B cells or post-germinal center neoplasms (B cell chronic lymphocytic leukemia and multiple myeloma) (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Cyclin-dependent kinases (CDKs) are serine/threonine kinases that are activated by cyclins and govern eukaryotic cell cycle progression. While CDK5 shares high sequence homology with its family members, it is thought mainly to function in postmitotic neurons to regulate the cytoarchitecture of these cells. Analogous to cyclins, the regulatory subunits p35 and p39 associate with and activate CDK5 despite the lack of sequence homology. CDK5 is ubiquitously expressed, with high levels of kinase activity detected primarily in the nervous system due to the narrow expression pattern of p35 and p39 in post-mitotic neurons. A large number of CDK5 substrates have been identified although no substrates have been specifically attributed to p35 or p39. Substrates of CDK5 include p35, PAK1, Src, β-catenin, tau, neurofilament-H, neurofilament-M, synapsin-1, APP, DARPP32, PP1-inhibitor, and Rb. p35 is rapidly degraded (T1/2 <20 min) by the ubiquitin-proteasome pathway (1). However, p35 stability increases as CDK5 kinase activity decreases, likely as a result of decreased phosphorylation of p35 at Thr138 by CDK5 (2). Proteolytic cleavage of p35 by calpain produces p25 upon neurotoxic insult, resulting in prolonged activation of CDK5 by p25. Research studies have shown accumulation of p25 in neurodegenerative diseases, such as Alzheimer's disease and amyotrophic lateral sclerosis (ALS) (3,4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: The stress-activated protein kinase/Jun-amino-terminal kinase SAPK/JNK is potently and preferentially activated by a variety of environmental stresses including UV and gamma radiation, ceramides, inflammatory cytokines, and in some instances, growth factors and GPCR agonists (1-6). As with the other MAPKs, the core signaling unit is composed of a MAPKKK, typically MEKK1-MEKK4, or by one of the mixed lineage kinases (MLKs), which phosphorylate and activate MKK4/7. Upon activation, MKKs phosphorylate and activate the SAPK/JNK kinase (2). Stress signals are delivered to this cascade by small GTPases of the Rho family (Rac, Rho, cdc42) (3). Both Rac1 and cdc42 mediate the stimulation of MEKKs and MLKs (3). Alternatively, MKK4/7 can be activated in a GTPase-independent mechanism via stimulation of a germinal center kinase (GCK) family member (4). There are three SAPK/JNK genes each of which undergoes alternative splicing, resulting in numerous isoforms (3). SAPK/JNK, when active as a dimer, can translocate to the nucleus and regulate transcription through its effects on c-Jun, ATF-2, and other transcription factors (3,5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: CD44 is a type I transmembrane glycoprotein that mediates cell-cell and cell-matrix interaction through its affinity for hyaluronic acid (HA) and possibly through other parts of the extracellular matrix (ECM). CD44 is highly polymorphic, possesses a number of alternative splice variants and undergoes extensive post-translational modifications (1,2). Increased surface levels of CD44 are characteristic of T cell activation, and expression of the protein is upregulated during the inflammatory response. Research studies have shown that interactions between CD44 and HER2 are linked to an increase in ovarian carcinoma cell growth (1-3). CD44 interacts with ezrin, radixin and moesin (ERM), linking the actin cytoskeleton to the plasma membrane and the ECM (4-6). CD44 is constitutively phosphorylated at Ser325 in resting cells. Activation of PKC results in phosphorylation of Ser291, dephosphorylation of Ser325, disassociation of ezrin from CD44, and directional motility (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunofluorescence (Frozen), Immunoprecipitation, Western Blotting

Background: Synaptotagmin 1 (SYT1) is an integral membrane protein found in synaptic vesicles thought to play a role in vesicle trafficking and exocytosis (1). Individual SYT1 proteins are composed of an amino-terminal transmembrane region, a central linker region and a pair of carboxy-terminal C2 domains responsible for binding Ca2+ (2). The C2 domains appear to be functionally distinct, with the C2A domain responsible for regulating synaptic vesicle fusion in a calcium-dependent manner during exocytosis while the C2B domain allows for interaction between adjacent SYT1 proteins (3). Because synaptotagmin 1 binds calcium and is found in synaptic vesicles, this integral membrane protein is thought to act as a calcium sensor in fast synaptic vesicle exocytosis. Evidence suggests possible roles in vesicle-mediated endocytosis and glucose-induced insulin secretion as well (4,5). SYT1 binds several different SNARE proteins during calcium-mediated vesicle endocytosis and an association between SYT1 and the SNARE protein SNAP-25 is thought to be a key element in vesicle-mediated exocytosis (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: CDK-activating kinase (CAK) is a complex of CDK7 and cyclin H. The complex is involved in cell cycle regulation by phosphorylating an activating residue in the T-loop domain of cdks (1). Regulation of CAK activity is mediated by T-loop phosphorylation and by association with MAT1, both of which enhance its kinase activity toward the CTD of RNA polymerase II (2,3) and other substrates such as p53 (4). CAK is an essential component of the transcription complex TFIIH and may interact directly with TFIIH helicases (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Western Blotting

Background: Modulation of chromatin structure plays a critical role in the regulation of transcription and replication of the eukaryotic genome. The nucleosome, made up of four core histone proteins (H2A, H2B, H3, and H4), is the primary building block of chromatin. In addition to the growing number of post-translational histone modifications regulating chromatin structure, cells can also exchange canonical histones with variant histones that can directly or indirectly modulate chromatin structure (1). CENP-A, also known as the chromatin-associated protein CSE4 (capping-enzyme suppressor 4-p), is an essential histone H3 variant that replaces canonical histone H3 in centromeric heterochromatin (2). The greatest divergence between CENP-A and canonical histone H3 occurs in the amino-terminal tail of the protein, which binds linker DNA between nucleosomes and facilitates proper folding of centromeric heterochromatin (3). The amino-terminal tail of CENP-A is also required for recruitment of other centromeric proteins (CENP-C, hSMC1, hZW10), proper kinetochore assembly and chromosome segregation during mitosis (4). Additional sequence divergence in the histone fold domain is responsible for correct targeting of CENP-A to the centromere (5). Many of the functions of CENP-A are regulated by phosphorylation (6,7). Aurora A-dependent phosphorylation of CENP-A on Ser7 during prophase is required for proper targeting of Aurora B to the inner centromere in prometaphase, proper kinetochore/microtubule attachment and proper alignment of chromosomes during mitosis (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting

Background: Lipin 1 was identified as a nuclear protein required for adipose tissue development (1). The expression of Lipin 1 is induced during adipocyte differentiation (1). The abnormal development of adipose tissues caused by mutations in the lipin 1 gene results in lipodystrophy, a condition associated with low body fat, fatty liver, hypertriglyceridemia, and insulin resistance (1). Lipin 1 plays a role in lipid metabolism in various tissues and cell types including liver, muscle, adipose tissues, and neuronal cell lines (2-4). It has dual functions at the molecular level: Lipin 1 serves as a transcriptional coactivator in liver, and a phosphatidate phosphatase in triglyceride and phospholipid biosynthesis pathways (5). Lipin 1 is regulated by mTOR, illustrating a connection between adipocyte development and nutrient-sensing pathways (6). It also mediates hepatic insulin signaling by TORC2/CRTC2 (7).