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Polyclonal Antibody Integral to Endoplasmic Reticulum Membrane

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

Application Methods: Western Blotting

Background: Secretory and transmembrane proteins are synthesized on polysomes and translocated into the endoplasmic reticulum (ER). Inside the ER, these proteins are often modified by disulfide bond formation, amino-linked glycosylation and folding. To help proteins fold properly, the ER contains a pool of molecular chaperones including BiP. BiP was identified as an immunoglobulin heavy chain binding protein in pre-B cells (1,2). It was also found to be induced at the protein level by glucose starvation (3). When protein folding is disturbed inside ER, BiP synthesis is increased. Subsequently, BiP binds to misfolded proteins to prevent them from forming aggregates and assists in proper refolding (4).

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

Application Methods: Immunoprecipitation, Western Blotting

Background: Ca2+ is a key second messenger in many intracellular signaling pathways. Ca2+ signals control many cellular functions ranging from short-term responses such as contraction and secretion to longer-term regulation of cell growth and proliferation (1,2). Stromal interaction molecules (STIMs) function as Ca2+ sensors that detect changes in Ca2+ content in intracellular Ca2+ stores (3). STIM1 is conserved, ubiquitously expressed, and functions as an endoplasmic reticulum (ER) Ca2+ sensor that migrates from the ER Ca2+ store to the plasma membrane where it activates calcium-release-activated calcium (CRAC) channels when the ER Ca2+ store is low (4). STIM1 is a potential tumor suppressor; defects in STIM1 may cause rhabdomyosarcoma and rhabdoid tumors (5). STIM1 can either homodimerize or form heterodimers with STIM2. STIM2 possesses a high sequence identity to STIM1 and can function as an inhibitor of STIM1-mediated plasma membrane store-operated Ca2+ entry (6). However, further investigation is required to elucidate the true physiological function of STIM2.

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: Wolfram syndrome protein (WFS1) is an 890 amino acid protein that contains a cytoplasmic N-terminal domain, followed by nine-transmembrane domains and a luminal C-terminal domain. WFS1 is predominantly localized to the endoplasmic reticulum (ER) (1) and its expression is induced in response to ER stress, partially through transcriptional activation (2,3). Research studies have shown that mutations in the WFS1 gene lead to Wolfram syndrome, an autosomal recessive neurodegenerative disorder defined by young-onset, non-immune, insulin-dependent diabetes mellitus and progressive optic atrophy (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Dog, Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: Autocrine motility factor receptor (AMFR/gp78) is a putative seven transmembrane domain G protein-coupled receptor that functions, in part, at the cell surface as a cytokine receptor for autocrine motility factor/phosphoglucose isomerase (AMF/PGI). AMFR is also localized to an intracellular mitochondria-associated smooth ER domain where it functions as an E3 ubiquitin ligase (1). AMFR function, as both a cytokine receptor and ubiquitin ligase, is linked to a variety of cellular signaling cascades associated with metastasis development and increased invasiveness. AMFR was initially proposed to be a RING-H2 E3 ubiquitin ligase after sequence analysis identified a catalytic RING finger and CUE motif, which are responsible for ubiquitin ligase activity and ubiquitin binding, respectively (2,3). Indeed, AMFR is a key component and amongst the best characterized ubiquitin ligases of the endoplasmic reticulum associated degradation (ERAD) machinery, a process involving recognition of misfolded proteins, ubiquitination, deglycosylation, retro-translocation to the cytosol, and targeting to the proteasome (4). Recent studies have shown that AMFR plays an important role in cholesterol homeostasis via the sterol-mediated ubiquitination of HMG-CoA reductase and its cofactor Insig-1 (5,6). Furthermore, AMFR has been implicated in the degradation of apolipoprotein B100 (7). It was recently reported that AMFR degrades the metastasis suppressor KAI-1/CD-82, representing the first evidence that AMFR ubiquitin ligase activity is involved in metastasis development (8). Increased expression of AMFR correlates with a high incidence of recurrence and reduced survival in patients with bladder, colorectal, and gastric cancers (9-11).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: CD8+ cytotoxic T cells recognize peptides presented by MHC class I molecules on the surface of infected cells and tumor cells. The transporters associated with antigen processing 1 and 2 (TAP1 and TAP2) form the TAP complex which resides on the ER membrane and transports peptides from the cytoplasm into the ER for loading onto MHC class I molecules (1-8). In addition, TAP localized to endosomal membranes is important for cross-presentation by dendritic cells (9,10). IFN-γ produced by T cells and NK cells in response to infection causes upregulation of TAP1 and TAP2, resulting in increased antigen presentation to T cells (11). Some viral proteins inhibit TAP function or downregulate TAP expression resulting in viral immune evasion (12,13). In addition, investigators have observed reduced TAP expression in a variety of tumor types, and it is thought to be one mechanism for tumor immune evasion (14).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Western Blotting

Background: CD8+ cytotoxic T cells recognize peptides presented by MHC class I molecules on the surface of infected cells and tumor cells. The transporters associated with antigen processing 1 and 2 (TAP1 and TAP2) form the TAP complex which resides on the ER membrane and transports peptides from the cytoplasm into the ER for loading onto MHC class I molecules (1-8). In addition, TAP localized to endosomal membranes is important for cross-presentation by dendritic cells (9,10). IFN-γ produced by T cells and NK cells in response to infection causes upregulation of TAP1 and TAP2, resulting in increased antigen presentation to T cells (11). Some viral proteins inhibit TAP function or downregulate TAP expression resulting in viral immune evasion (12,13). In addition, investigators have observed reduced TAP expression in a variety of tumor types, and it is thought to be one mechanism for tumor immune evasion (14).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: Neurite outgrowth inhibition protein (Nogo, RTN4) is a reticulon family protein that was identified as an axonal growth inhibitor of the central nervous system (CNS). Nogo occurs as three major isoforms (Nogo-A, Nogo-B, and Nogo-C) that share a common carboxy terminus of 188 amino acids. Nogo-A is transmembrane protein enriched in the endoplasmic reticulum and expressed at high levels in the CNS, and more weakly in skeletal and heart muscle (1-3). Expression of Nogo-A decreases with increasing age during brain development. In the adult CNS, negative regulation of neuronal growth leads to stabilization of the CNS wiring at the expense of extensive plastic rearrangements. Nogo-A meditates inhibition of neurite growth together with the nogo receptor 1 (NgR1), the p75 neurotrophin receptor p75NTR, and the transmembrane LINGO1 protein. This Nogo receptor signaling complex activates the RhoA/ROCK pathway, which collapses neuronal growth cones and inhibits axonal growth in the CNS following traumatic brain injury. Research studies suggest that inhibition of Nogo A may be beneficial to patients with traumatic brain injury. Nogo-B and Nogo-C inhibit BACE1 activity and amyloid precursor protein processing, suggesting a role in cell survival (4).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: FAM134B (family with sequence similarity 134, member B), also referred to as JK-1 and RETREG1, is a cis-Golgi endoplasmic reticulum (ER) transmembrane protein that plays a role in ER homeostasis and may contribute to several human diseases (1). FAM134B contains a conserved LC3 interacting domain (LIR) that facilitates binding to LC3 and GABARAP family members and targets impaired ER to the autophagsome for degradation by ER-phagy (2). Deletion of FAM134B leads to ER expansion and stress-induced apoptosis (2). Expression of FAM134B has been linked to a number of pathological conditions, including viral infection, cancer, and neuronal disorders (1). FAM134B can potentially inhibit viral infection, as demonstrated by studies of FAM134B knockouts that resulted in significantly higher rates of Ebola virus replication (3). Mutations in FAM134B that lead to an accumulation of mis-folded proteins have also been associated with neuronal sensory disorders (2, 4, 5). The expression and mutational state of FAM134B can also have varying effects on cancer. Oncogenic effects of FAM134B were described in esophageal squamous carcinoma; whereas, it appears to have tumor suppressor activity in colorectal cancer (6-8).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Sarcoplasmic and endoplasmic reticulum Ca2+ ATPases (SERCA) are members of a highly conserved family of Ca2+ pumps (1). SERCA pumps transport Ca2+ from the cytosol to the sarcoplasmic and endoplasmic reticulum lumen against a large concentration gradient (1). ATP2A1 (SERCA1) is a fast-twitch, skeletal muscle sarcoplasmic reticulum Ca2+ ATPase (2). Research studies have shown that mutations in the ATP2A1 gene cause an autosomal recessive muscle disorder known as Brody myopathy, which is characterized by muscle cramping and impaired muscle relaxation associated with exercise (1-3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: Western Blotting

Background: Glucuronidation is a major pathway that enhances the elimination of lipophilic xenobiotics and endobiotics to more more water soluble compounds for excretion (1,2). The UDP-glucuronosyltransferase (UGT) superfamily catalyzes the glucuronidation of the glycosyl group of a nucleotide sugar to a variety of endogenous and exogenous compounds. Over 100 UGT mammalian gene products have been described and have been divided into subfamilies based on sequence identities (3). The UGT1 subfamily consists of a number of gene products resulting from alternative splicing. These UGT products can differ in tissue expression and substrate specificity. Also, marked differences in the individual expression of UGT isoforms can account for differences in drug metabolism.

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

Application Methods: Western Blotting

Background: The ATP2A2 (SERCA2) calcium pump is one of several sarcoplasmic and endoplasmic reticulum Ca2+-ATPases responsible for regulating calcium transport across intracellular membranes (1). Multiple isoforms have been isolated, with ATP2A2a (SERCA2a) found predominantly in the sarcoplasmic reticulum of muscle cells and ATP2A2b (SERCA2b) more ubiquitously expressed in the endoplasmic reticulum of most cell types (2). An isoform containing a truncated carboxy region (ATP2A2c) is expressed in epithelial and hematopoietic cell lines and may be involved in monocyte differentiation (3). Post-translational modification of ATP2A2 (SERCA2), including phosphorylation and tyrosine nitration, modify Ca2+ -ATPase activity and calcium transport (4,5). Mutation in the corresponding ATP2A2 (SERCA2) gene results in Darier disease, a skin disorder characterized by the presence of dark, keratotic papules or rash found on the head and torso (6).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Monkey

Application Methods: Immunoprecipitation, Western Blotting

Background: Presenilin 1 and presenilin 2 are transmembrane proteins belonging to the presenilin family. Mutation of presenilin genes has been linked to early onset of Alzheimer disease, probably due to presenilin's associated γ-secretase activity for amyloid-β protein processing (1,2). Endogenous presenilin mainly exists in a heterodimeric complex formed from the endoproteolytically processed amino-terminal (34 kDa) and carboxy-terminal (~20, 22, 23 kDa) fragments (CTF) (2,3).

$260
100 µl
APPLICATIONS
REACTIVITY
Mouse, Rat

Application Methods: Western Blotting

Background: Sarcoplasmic and endoplasmic reticulum Ca2+ ATPases (SERCA) are members of a highly conserved family of Ca2+ pumps (1). SERCA pumps transport Ca2+ from the cytosol to the sarcoplasmic and endoplasmic reticulum lumen against a large concentration gradient (1). ATP2A1 (SERCA1) is a fast-twitch, skeletal muscle sarcoplasmic reticulum Ca2+ ATPase (2). Research studies have shown that mutations in the ATP2A1 gene cause an autosomal recessive muscle disorder known as Brody myopathy, which is characterized by muscle cramping and impaired muscle relaxation associated with exercise (1-3).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Western Blotting

Background: Erlin-1 and erlin-2 (SPFH1 and SPFH2) are SPFH domain-containing proteins that belong to the prohibitin family (1,2). The N-termal domain of erlin proteins contains ER-targeting sequences responsible for their translocation to the endoplasmic reticulum (ER) (3). In the ER, erlin-1 and erlin-2 specifically associate with the detergent resistant lipid raft microdomain of the membrane (3). Erlin-1 may be involved in dentritic cell activation (4) and erlin-2 has been shown to regulate the ER-associated degradation (ERAD) pathway by interacting with endogenous substrates and resulting in their polyubiquitination and degradation (5).

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

Application Methods: Immunoprecipitation, Western Blotting

Background: Presenilin 1 and presenilin 2 are transmembrane proteins belonging to the presenilin family. Mutation of presenilin genes has been linked to early onset of Alzheimer disease, probably due to presenilin's associated γ-secretase activity for amyloid-β protein processing (1,2). Endogenous presenilin mainly exists in a heterodimeric complex formed from the endoproteolytically processed amino-terminal (34 kDa) and carboxy-terminal (~20, 22, 23 kDa) fragments (CTF) (2,3).

$303
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse, Rat

Application Methods: 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, Monkey, Mouse, Rat

Application Methods: Immunoprecipitation, Western Blotting

Background: BAP31 (B-cell receptor-association protein 31) is a transmembrane protein associated with the endplasmic reticulum (ER) and ER-Golgi intermediates and has been implicated in protein trafficking and apoptosis (1,2). During apoptosis Bap31 is cleaved by caspase-8 at two carboxy-terminal sites which can then direct apoptotic signals between the ER and mitochondria (2-4). Association of BAP31 with the anti-apoptotic proteins Bcl-2 or Bcl-xL could function to regulate this ER-mitochondrial pathway (2,5). Several studies have shown that BAP31 can control the trafficking of select proteins between the ER and Golgi apparatus and can affect the transport of proteins to the cell surface (6-10).

$260
100 µl
APPLICATIONS
REACTIVITY
Human, Mouse

Application Methods: Immunoprecipitation, Western Blotting

Background: Erlin-1 and erlin-2 (SPFH1 and SPFH2) are SPFH domain-containing proteins that belong to the prohibitin family (1,2). The N-termal domain of erlin proteins contains ER-targeting sequences responsible for their translocation to the endoplasmic reticulum (ER) (3). In the ER, erlin-1 and erlin-2 specifically associate with the detergent resistant lipid raft microdomain of the membrane (3). Erlin-1 may be involved in dentritic cell activation (4) and erlin-2 has been shown to regulate the ER-associated degradation (ERAD) pathway by interacting with endogenous substrates and resulting in their polyubiquitination and degradation (5).

$260
100 µl
APPLICATIONS
REACTIVITY
Human

Application Methods: Immunoprecipitation, Western Blotting

Background: Members of the Toll-like receptor (TLR) family, named for the closely related Toll receptor in Drosophila, play a pivotal role in innate immune responses (1-4). TLRs recognize conserved motifs found in various pathogens and mediate defense responses (5-7). Triggering of the TLR pathway leads to the activation of NF-κB and subsequent regulation of immune and inflammatory genes (4). The TLRs and members of the IL-1 receptor family share a conserved stretch of approximately 200 amino acids known as the Toll/Interleukin-1 receptor (TIR) domain (1). Upon activation, TLRs associate with a number of cytoplasmic adaptor proteins containing TIR domains, including myeloid differentiation factor 88 (MyD88), MyD88-adaptor-like/TIR-associated protein (MAL/TIRAP), Toll-receptor-associated activator of interferon (TRIF), and Toll-receptor-associated molecule (TRAM) (8-10). This association leads to the recruitment and activation of IRAK1 and IRAK4, which form a complex with TRAF6 to activate TAK1 and IKK (8,11-14). Activation of IKK leads to the degradation of IκB, which normally maintains NF-κB in an inactive state by sequestering it in the cytoplasm.

$260
100 µl
APPLICATIONS
REACTIVITY
Bovine, Hamster, Human, Mouse, Pig, Rat, Zebrafish

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

Background: The 21-24 kDa integral proteins, caveolins, are the principal structural components of the cholesterol/sphingolipid-enriched plasma membrane microdomain caveolae. Three members of the caveolin family (caveolin-1, -2, and -3) have been identified with different tissue distributions. Caveolins form hetero- and homo-oligomers that interact with cholesterol and other lipids (1). Caveolins are involved in diverse biological functions, including vesicular trafficking, cholesterol homeostasis, cell adhesion, and apoptosis, and are also implicated in neurodegenerative disease (2). Caveolins interact with multiple signaling molecules such as Gα subunit, tyrosine kinase receptors, PKCs, Src family tyrosine kinases, and eNOS (1,2). It is believed that caveolins serve as scaffolding proteins for the integration of signal transduction. Phosphorylation at Tyr14 is essential for caveolin association with SH2 or PTB domain-containing adaptor proteins such as GRB7 (3-5). Phosphorylation at Ser80 regulates caveolin binding to the ER membrane and entry into the secretory pathway (6).