VAPB (Vesicle-associated Membrane Protein-associated Protein B/C, VAMP-B/VAMP-C, VAMP-associated Protein B/C, VAP-B/VAP-C, UNQ484/PRO983)

Vesicle-associated membrane protein associated protein B is an~30kD ubiquitously expressed type IV transmembrane protein belonging to the VAP family. It is found in endoplasmic reticulum (ER), Golgi and other membranes as a homodimer or a heterodimer with VAP-A, probably associating through a GxxxG motif in the transmembrane regions. Human VAP-B cDNA encodes 243aa that include a 222aa cytoplasmic domain and a 21aa C-terminal membrane anchor. The cytoplasmic domain contains a mobile sperm protein (MSP) domain aa7-124 and a coiled-coil region aa159-196. Human VAP-B shares 90%, 89%, 96%, 96% and 94% aa identity with mouse, rat, canine, bovine and porcine VAP-B, respectively. VAP-A and VAP-B MSP domains recruit FFAT motif-containing proteins to the cytosolic surface of ER membranes. FFAT proteins mediate many of the effects of VAPs on regulation of membrane transport, phospholipid biosynthesis, microtubule organization, and the unfolded protein response. VAPs also interact with some SNARE and viral proteins. A human polymorphism of VAP-B, P56S, is found in three familial motor neuron diseases, notably the amylotrophic lateral sclerosis variant ALS8. It produces a non-functional protein that can dimerize with and inhibit function of normal VAP-B, leading formation of intracellular aggregates and increased ER-stress-induced death of motor neurons. It can also promote cleavage and secretion of soluble VAP-B, which can then function as a ligand for EPH receptors. A naturally occurring 99aa isoform of VAP-B that diverges at 71aa within the MSP domain is termed VAP-C. It also appears to be a negative regulator of VAP-A and VAP-B. While VAP-B is used by hepatitis C virus (HCV) for its propagation, VAP-C inhibits HCV propagation.\n\nApplications:\nSuitable for use in Immunohistochemistry. Other applications not tested.\n\nRecommended Dilution:\nImmunohistochemistry: 8-25ug/ml\nOptimal dilutions to be determined by the researcher.\n\nStorage and Stability:\nLyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Reconstituted product is stable for 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

V2024-15C

Size

100ug

Applications

IHC

Hosts

Mouse

Reactivities

Hum

Form

Supplied as a lyophilized powder in PBS, trehalose. Reconstitute with sterile PBS to 0.5mg/ml.

P Type

Mab

Purity

Purified by Protein A/G affinity chromatography.

Isotype

IgG2B

References

1. Nishimura, Y. et al. (1999) Biochem. Biophys. Res. Commun. 254:21. 2. Lev, S. et al. (2008) Trends Cell Biol. 18:282. 3. Peretti, D. et al. (2008) Mol. Biol. Cell 19:3871. 4. Kaiser, S.E. et al. (2005) Structure 13:1035. 5. Prosser, D.C. et al. (2008) J. Cell Sci. 121:3052. 6. Gkogkas, C. et al. (2008) Hum. Mol. Genet. 17:1517. 7. Suzuki, H. et al. (2009) J. Neurochem. 108:973. 8. Tsuda, H. et al. (2008) Cell 133:963. 9. Kukihara, H. et al. (2009) J. Virol. 83:7959.

Additional Info

Recognizes human VAP-B. Species sequence homology: recombinant rat VAP-B (50%). Does not react with recombinant human VAP-A.