Alternative titles; symbols
HGNC Approved Gene Symbol: SEC22B
Cytogenetic location: 1p12 Genomic coordinates (GRCh38) : 1:120,150,898-120,176,520 (from NCBI)
Hay et al. (1997) isolated mouse Sec22b cDNAs and determined that the Sec22b protein is distinct from the previously identified rat SEC22A protein (612442). Sequence analysis revealed that mouse Sec22b is a cytoplasmically oriented, C-terminally anchored integral membrane protein.
Mao et al. (1998) identified an umbilical cord blood CD34-positive cell cDNA encoding the human homolog of Sec22b. The predicted human protein contains 215 amino acids.
By analysis of radiation hybrids, Mao et al. (1998) mapped the human SEC22B gene to chromosome 1q21.2-q21.3.
In S. cerevisiae, the vesicle trafficking protein complexes directing transport between the endoplasmic reticulum (ER) and Golgi appear to include Sed5 (see syntaxin-5; 603189), proposed to be a cis-Golgi receptor protein, and Sec22 and Bet1 (605456), potential Sed5 docking partners localized on ER-derived vesicles. The Sly1 protein may bind to and regulate the activity of Sed5 for docking with ER-derived vesicle proteins. See membrin (GOSR2; 604027). Hay et al. (1997) isolated a rat liver protein complex representing an intermediate in ER-to-Golgi transfer reactions. The complex contained syntaxin-5, GOS28 (604026), the rat homologs of Bet1 and Sly1, and 2 novel proteins, rat SEC22B and membrin. By immunofluorescence of mammalian cells expressing epitope-tagged mouse Sec22b, Hay et al. (1997) found that Sec22b and membrin accumulated primarily at the ER. Other members of the complex localized to Golgi membranes, indicating that the complex recapitulates vesicle docking between distinct organelles in the ER/Golgi transport cycle. Expression of recombinant membrin and Sec22b disrupted normal trafficking, demonstrating that these proteins regulate ER-to-Golgi trafficking.
To fuse transport vesicles with target membranes, proteins of the SNARE complex must be located on both the vesicle and the target membrane. In yeast, 4 integral membrane proteins, Sed5, Bos1, Sec22, and Bet1 each are believed to contribute a single helix to form the SNARE complex that is needed for transport from endoplasmic reticulum to Golgi. This generates a 4-helix bundle, which ultimately mediates the actual fusion event. Parlati et al. (2000) explored how the anchoring arrangement of the 4 helices affects their ability to mediate fusion. Parlati et al. (2000) reconstituted 2 populations of phospholipid bilayer vesicles, with the individual SNARE proteins distributed in all possible combinations between them. Of the 8 nonredundant permutations of 4 subunits distributed over 2 vesicle populations, only 1 resulted in membrane fusion. Fusion occurred only when the v-SNARE Bet1 is on 1 membrane and the syntaxin heavy chain Sed5 and its 2 light chains, Bos1 and Sec22, are on the other membrane, where they form a functional t-SNARE. Thus, each SNARE protein is topologically restricted by design to function either as a v-SNARE or as part of a t-SNARE complex.
Hay, J. C., Chao, D. S., Kuo, C. S., Scheller, R. H. Protein interactions regulating vesicle transport between the endoplasmic reticulum and Golgi apparatus in mammalian cells. Cell 89: 149-158, 1997. [PubMed: 9094723] [Full Text: https://doi.org/10.1016/s0092-8674(00)80191-9]
Mao, M., Fu, G., Wu, J.-S., Zhang, Q.-H., Zhou, J., Kan, L.-X., Huang, Q.-H., He, K.-L., Gu, B.-W., Han, Z.-G., Shen, Y., Gu, J., Yu, Y.-P., Xu, S.-H., Wang, Y.-X., Chen, S.-J., Chen, Z. Identification of genes expressed in human CD34+ hematopoietic stem/progenitor cells by expressed sequence tags and efficient full-length cDNA cloning. Proc. Nat. Acad. Sci. 95: 8175-8180, 1998. [PubMed: 9653160] [Full Text: https://doi.org/10.1073/pnas.95.14.8175]
Parlati, F., McNew, J. A., Fukuda, R., Miller, R., Sollner, T. H., Rothman, J. E. Topological restriction of SNARE-dependent membrane fusion. Nature 407: 194-198, 2000. [PubMed: 11001058] [Full Text: https://doi.org/10.1038/35025076]