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Polyclonal Antibody Calcium-Dependent Protein Binding

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Western Blotting

Background: Annexin A7/ANXA7 is a member of the annexin family of calcium/phospholipid-binding proteins, and is involved in the process of membrane fusion and exocytosis (1). Annexin A7 is a GTPase, and both GTP-binding and PKC activity are important in regulating protein function (2,3). Membrane binding of annexin A7 is calcium dependent (4). Two isoforms exist due to alternative splicing. Subcellular localization of annexin A7 has been shown to be in the cytoplasm, vesicular structures, membrane and in adrenal chromaffin granules (5,6). Nuclear localization has been shown in the developing mouse central nervous system as well as in adult mouse brain (7). Annexin A7-deficient mouse studies show that the protein has a role in insulin secretion and calcium signaling (8) as well as cardiac intracellular calcium homeostasis electrical stability (9). The gene for annexin A7 is a putative tumor suppressor (10), and alterations in the copy number have been reported in prostate cancer (11). Annexin A7 expression has also been correlated with survival in human glioblastoma patients (12), and haploinsufficiency in mice may promote genetic instability leading to tumorigenesis (13).

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

Application Methods: Flow Cytometry, 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

Application Methods: Western Blotting

Background: MMP-13 (collagenase 3) belongs to the matrix metalloproteinase (MMP) superfamily of enzymes that targets many extracellular proteins, including other proteases, growth factors, cell surface receptors, and adhesion molecules (1, 2). MMP-13 is a member of a subgroup of collagenases (including MMP-1, MMP-8, and MMP-18) that play an even more important function targeting fibrillar collagen. MMP-13 is synthesized as a latent proenzyme, and proteolytic removal of the inhibitory propeptide domain is required for enzyme activation. MMP-13 protein levels are regulated at the transcriptional level, via specific transcription factors and via promoter DNA methylation (3, 4). MMP-13 preferentially cleaves Type II collagen, and research studies have shown that aberrant upregulation of MMP-13 activity can lead to cartilage loss and osteoarthritis (5, 6). In addition, MMP-13 has been shown to promote cancer development, in part through enhancing tumor angiogenesis and metastases (7-9), suggesting that collagenase activity may serve as a useful marker of tumor progression (10).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Despite their relatively small size (8-12 kDa) and uncomplicated architecture, S100 proteins regulate a variety of cellular processes such as cell growth and motility, cell cycle progression, transcription, and differentiation. To date, 25 members have been identified, including S100A1-S100A18, trichohyalin, filaggrin, repetin, S100P, and S100Z, making it the largest group in the EF-hand, calcium-binding protein family. Interestingly, 14 S100 genes are clustered on human chromosome 1q21, a region of genomic instability. Research studies have demonstrated that significant correlation exists between aberrant S100 protein expression and cancer progression. S100 proteins primarily mediate immune responses in various tissue types but are also involved in neuronal development (1-4).Each S100 monomer bears two EF-hand motifs and can bind up to two molecules of calcium (or other divalent cation in some instances). Structural evidence shows that S100 proteins form antiparallel homo- or heterodimers that coordinate binding partner proximity in a calcium-dependent (and sometimes calcium-independent) manner. Although structurally and functionally similar, individual members show restricted tissue distribution, are localized in specific cellular compartments, and display unique protein binding partners, which suggests that each plays a specific role in various signaling pathways. In addition to an intracellular role, some S100 proteins have been shown to act as receptors for extracellular ligands or are secreted and exhibit cytokine-like activities (1-4).

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

Application Methods: Western Blotting

Background: The annexin superfamily consists of 13 calcium or calcium and phospholipid binding proteins with high biological and structural homology (1). Annexin-1 (ANXA1) is the first characterized member of the annexin family of proteins and is able to bind to cellular membranes in a calcium-dependent manner, promoting membrane fusion and endocytosis (2-4). Annexin A1 has anti-inflammatory properties and inhibits phospholipase A2 activity (5,6). Annexin A1 can accumulate on internalized vesicles after EGF-stimulated endocytosis and may be required for a late stage in inward vesiculation (7). Phosphorylation by PKC, EGFR, and Chak1 results in inhibition of annexin A1 function (8-10). Annexin A1 has also been identified as one of the 'eat-me' signals on apoptotic cells that are to be recognized and ingested by phagocytes (11). Annexin A1, as an endogenous anti-inflammatory mediator, has roles in many diverse cellular functions, such as membrane aggregation, inflammation, phagocytosis, proliferation, apoptosis, and tumorigenesis and cancer development (12-14).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse

Application Methods: Western Blotting

Background: Troponin, working in conjunction with tropomyosin, functions as a molecular switch that regulates muscle contraction in response to changes in the intracellular Ca2+ concentration. Troponin consists of three subunits: the Ca2+-binding subunit troponin C (TnC), the tropomyosin-binding subunit troponin T (TnT), and the inhibitory subunit troponin I (TnI) (1). In response to β-adrenergic stimulation of the heart, Ser23 and Ser24 of TnI (cardiac) are phosphorylated by PKA and PKC. This phosphorylation stimulates a conformational change of the regulatory domain of TnC, reduces the association between TnI and TnC, and decreases myofilament Ca2+ sensitivity by reducing the Ca2+ binding affinity of TnC (1-3).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Troponin, working in conjunction with tropomyosin, functions as a molecular switch that regulates muscle contraction in response to changes in the intracellular Ca2+ concentration. Troponin consists of three subunits: the Ca2+-binding subunit troponin C (TnC), the tropomyosin-binding subunit troponin T (TnT), and the inhibitory subunit troponin I (TnI) (1). In response to β-adrenergic stimulation of the heart, Ser23 and Ser24 of TnI (cardiac) are phosphorylated by PKA and PKC. This phosphorylation stimulates a conformational change of the regulatory domain of TnC, reduces the association between TnI and TnC, and decreases myofilament Ca2+ sensitivity by reducing the Ca2+ binding affinity of TnC (1-3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Despite their relatively small size (8-12 kDa) and uncomplicated architecture, S100 proteins regulate a variety of cellular processes such as cell growth and motility, cell cycle progression, transcription, and differentiation. To date, 25 members have been identified, including S100A1-S100A18, trichohyalin, filaggrin, repetin, S100P, and S100Z, making it the largest group in the EF-hand, calcium-binding protein family. Interestingly, 14 S100 genes are clustered on human chromosome 1q21, a region of genomic instability. Research studies have demonstrated that significant correlation exists between aberrant S100 protein expression and cancer progression. S100 proteins primarily mediate immune responses in various tissue types but are also involved in neuronal development (1-4).Each S100 monomer bears two EF-hand motifs and can bind up to two molecules of calcium (or other divalent cation in some instances). Structural evidence shows that S100 proteins form antiparallel homo- or heterodimers that coordinate binding partner proximity in a calcium-dependent (and sometimes calcium-independent) manner. Although structurally and functionally similar, individual members show restricted tissue distribution, are localized in specific cellular compartments, and display unique protein binding partners, which suggests that each plays a specific role in various signaling pathways. In addition to an intracellular role, some S100 proteins have been shown to act as receptors for extracellular ligands or are secreted and exhibit cytokine-like activities (1-4).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Western Blotting

Background: Synapsins, a group of at least five related members (synapsins Ia, Ib, IIa, IIb, and IIIa), are abundant brain proteins essential for regulating neurotransmitter release (1,2). All synapsins contain a short amino-terminal domain that is highly conserved and phosphorylated by PKA or CaM kinase I (1). Phosphorylation of the synapsin amino-terminal domain at Ser9 inhibits its binding to phospholipids and dissociates synapsins from synaptic vesicles (2).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

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

Background: Myosin Va is a molecular motor protein involved in the transport of organelles, vesicles and other cellular cargo along actin filaments (reviewed in 1). The molecule consists of two identical heavy chains, which dimerize via helical domains in a coiled coil structure. The amino-terminal motor domains of the heavy chains contain both the ATPase and the actin-binding activities of myosin Va. The globular tail domains act in a regulatory capacity, binding the myosin Va cargo (2) or inhibiting motor activity by binding the head domains and preventing ATP consumption (3). Mutation of the murine dilute gene, which encodes myosin Va, causes defects in coat pigmentation as well as severe neurological defects (4). In melanocytes, the coiled coil structure of myosin Va is important in regulating the trafficking of melanosomes in conjunction with melanophilin and Rab27a (5). Myosin Va regulates trafficking and exocytosis of secretory granules in neuroendocrine cells (reviewed in 6) as well as RNA transport and distribution (7).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Western Blotting

Background: The 25 kDa synaptosome-associated protein (SNAP25) is a target membrane soluble, N-ethylmaleimide-sensitive factor attachment protein receptor (t-SNARE) that is found on neuronal presynaptic membranes. SNAP25 forms a core complex with the SNARE proteins syntaxin and synaptobrevin to mediate synaptic vesicle fusion with the plasma membrane during Ca2+-dependent exocytosis (1). This complex is responsible for exocytosis of the neurotransmitter γ-aminobutyric acid (GABA). Neurotransmitter release is inhibited by proteolysis of SNAP25 by botulinum toxins A and E (2). SNAP25 plays a secondary role as a Q-SNARE involved in endosome fusion; the protein is associated with genetic susceptibility to attention-deficit hyperactivity disorder (ADHD) (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Western Blotting

Background: The 25 kDa synaptosome-associated protein (SNAP25) is a target membrane soluble, N-ethylmaleimide-sensitive factor attachment protein receptor (t-SNARE) that is found on neuronal presynaptic membranes. SNAP25 forms a core complex with the SNARE proteins syntaxin and synaptobrevin to mediate synaptic vesicle fusion with the plasma membrane during Ca2+-dependent exocytosis (1). This complex is responsible for exocytosis of the neurotransmitter γ-aminobutyric acid (GABA). Neurotransmitter release is inhibited by proteolysis of SNAP25 by botulinum toxins A and E (2). SNAP25 plays a secondary role as a Q-SNARE involved in endosome fusion; the protein is associated with genetic susceptibility to attention-deficit hyperactivity disorder (ADHD) (3).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Western Blotting

Background: Calmodulin is a ubiquitously expressed small protein mediating many cellular effects such as short-term and long-term memory, nerve growth, inflammation, apoptosis, muscle contraction and intracellular movement (1). Upon binding of four Ca2+ ions, calmodulin undergoes conformational changes, allowing this complex to bind to and activate many enzymes including protein kinases, protein phosphatases, ion channels, Ca2+ pumps, nitric oxide synthase, inositol triphosphate kinase, and cyclic nucleotide phosphodiesterase (2,3). Since calmodulin binds Ca2+ in a cooperative fashion, small changes in cytosolic Ca2+ levels lead to large changes in the level of active calmodulin and its target proteins (4).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Synapsins, a group of at least five related members (synapsins Ia, Ib, IIa, IIb, and IIIa), are abundant brain proteins essential for regulating neurotransmitter release (1,2). All synapsins contain a short amino-terminal domain that is highly conserved and phosphorylated by PKA or CaM kinase I (1). Phosphorylation of the synapsin amino-terminal domain at Ser9 inhibits its binding to phospholipids and dissociates synapsins from synaptic vesicles (2).

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

Application Methods: Western Blotting

Background: DDX5 (DEAD box polypeptide 5), also known as p68, was first identified as a 68 kDa nuclear protein with similarity to translation initiation factor eIF-4A (1). DDX5 is a member of the DEAD box family of putative RNA helicases, defined by the presence of a conserved DEAD (Asp-Glu-Ala-Asp) motif that appears to function primarily in the regulation of RNA secondary structure. DDX5 exhibits ATP-dependent RNA helicase activity (2) and has been identified as a critical subunit of the DROSHA complex that regulates miRNA and rRNA processing (3,4). DDX may also regulate mRNA splicing (5) and has been shown to interact with HDAC1, where it can regulate promoter-specific transcription (6). DDX5 interacts with a diverse group of proteins, including Runx2, p53, Smad3, CBP, and p300 (7-10), suggesting an important role for DDX5 in a multitude of developmental processes. Notably, DDX5 may be involved in growth factor-induced epithelial mesechymal transition (EMT). Phosphorylation of DDX5 at Tyr593 following PDGF stimulation was shown to displace Axin from β-catenin; this prevented phosphorylation of β-catenin by GSK-3β, leading to Wnt-independent nuclear translocation of β-catenin (11) and increased transcription of c-Myc, cyclin D1, and Snai1 (12,13).

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Bovine, Human, Monkey, Mouse, Rat

Application Methods: Flow Cytometry, Western Blotting

Background: Rac and Cdc42 are members of the Rho-GTPase family. In mammals, Rac exists as three isoforms, Rac1, Rac2 and Rac3, which are highly similar in sequence. Rac1 and Cdc42, the most widely studied of this group, are ubiquitously expressed. Rac2 is expressed in cells of hematopoietic origin, and Rac3, while highly expressed in brain, is also found in many other tissues. Rac and Cdc42 play key signaling roles in cytoskeletal reorganization, membrane trafficking, transcriptional regulation, cell growth and development (1). GTP binding stimulates the activity of Rac/Cdc42, and the hydrolysis of GTP to GDP through the protein's intrinsic GTPase activity, rendering it inactive. GTP hydrolysis is aided by GTPase activating proteins (GAPs), while exchange of GDP for GTP is facilitated by guanine nucleotide exchange factors (GEFs). Another level of regulation is achieved through the binding of RhoGDI, a guanine nucleotide dissociation inhibitor, which retains Rho family GTPases, including Rac and Cdc42, in their inactive GDP-bound state (2,3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: CaMKIV is an important member of calcium/calmodulin-activated kinases. CaMKIV signaling has been related to long-term neural potentiation and memory (1,2), as well as T-cell receptor signaling (3). CaMKIV has catalytic and regulatory domains. The Ca2+/calmodulin-dependent CaMKK phosphorylates CaMKIV, releasing the autoinhibitory effect and thus activating the kinase (4-6). The activated CaMKIV further autophosphorylates itself at Thr196 (or Thr200 in human) to render the kinase constitutively active (5). The threonine phosphorylation state of CaMKIV can be downregulated by PP2A dephosphorylation.

$111
20 µl
$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

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

Background: Activation of protein kinase C (PKC) is one of the earliest events in a cascade that controls a variety of cellular responses, including secretion, gene expression, proliferation, and muscle contraction (1,2). PKC isoforms belong to three groups based on calcium dependency and activators. Classical PKCs are calcium-dependent via their C2 domains and are activated by phosphatidylserine (PS), diacylglycerol (DAG), and phorbol esters (TPA, PMA) through their cysteine-rich C1 domains. Both novel and atypical PKCs are calcium-independent, but only novel PKCs are activated by PS, DAG, and phorbol esters (3-5). Members of these three PKC groups contain a pseudo-substrate or autoinhibitory domain that binds to substrate-binding sites in the catalytic domain to prevent activation in the absence of cofactors or activators. Control of PKC activity is regulated through three distinct phosphorylation events. Phosphorylation occurs in vivo at Thr500 in the activation loop, at Thr641 through autophosphorylation, and at the carboxy-terminal hydrophobic site Ser660 (2). Atypical PKC isoforms lack hydrophobic region phosphorylation, which correlates with the presence of glutamic acid rather than the serine or threonine residues found in more typical PKC isoforms. The enzyme PDK1 or a close relative is responsible for PKC activation. A recent addition to the PKC superfamily is PKCμ (PKD), which is regulated by DAG and TPA through its C1 domain. PKD is distinguished by the presence of a PH domain and by its unique substrate recognition and Golgi localization (6). PKC-related kinases (PRK) lack the C1 domain and do not respond to DAG or phorbol esters. Phosphatidylinositol lipids activate PRKs, and small Rho-family GTPases bind to the homology region 1 (HR1) to regulate PRK kinase activity (7).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey, Mouse, Rat

Application Methods: Western Blotting

Background: Eukaryotic initiation factor 4E (eIF4E) binds to the mRNA cap structure to mediate the initiation of translation (1,2). eIF4E interacts with eIF4G, a scaffold protein that promotes assembly of eIF4E and eIF4A into the eIF4F complex (2). eIF4B is thought to assist the eIF4F complex in translation initiation. Upon activation by mitogenic and/or stress stimuli mediated by Erk and p38 MAPK, Mnk1 phosphorylates eIF4E at Ser209 in vivo (3,4). Two Erk and p38 MAPK phosphorylation sites in mouse Mnk1 (Thr197 and Thr202) are essential for Mnk1 kinase activity (3). The carboxy-terminal region of eIF4G also contains serum-stimulated phosphorylation sites, including Ser1108, Ser1148, and Ser1192 (5). Phosphorylation at these sites is blocked by the PI3 kinase inhibitor LY294002 and by the FRAP/mTOR inhibitor rapamycin.

$303
100 µl
APPLICATIONS
REACTIVITY
Rat

Application Methods: Western Blotting

Background: CaMKII is an important member of the calcium/calmodulin-activated protein kinase family, functioning in neural synaptic stimulation and T cell receptor signaling (1,2). CaMKII has catalytic and regulatory domains. Ca2+/calmodulin binding to the CaMKII regulatory domain relieves autoinhibition and activates the kinase (3). The activated CaMKII further autophosphorylates at Thr286 to render the kinase constitutively active (3). The threonine phosphorylation state of CaMKII can be regulated through PP1/PKA. PP1 (protein phosphatase 1) dephosphorylates phospho-CaMKII at Thr286. PKA (protein kinase A) prevents phospho-CaMKII (Thr286) dephosphorylation through an inhibitory effect on PP1 (4).