HGNC Approved Gene Symbol: RAB13
Cytogenetic location: 1q21.3 Genomic coordinates (GRCh38): 1:153,981,650-153,990,708 (from NCBI)
The Rab proteins comprise the largest group of Ras-associated small GTPases and in mammalian cells at least 40 proteins have been identified (Novick and Zerial, 1997). Rab proteins are specific regulators of vesicular traffic and the complexity of the Rab protein family correlates with the diversity of cellular vesicle transport routes. A different Rab protein may be required for each step of vesicular transport. For example, the yeast Sec4 protein appears to be required exclusively for the delivery of Golgi-derived secretory vesicles to the plasma membrane (Salminen and Novick, 1987). By screening a human intestinal epithelial cell (Caco-2) cDNA library with a degenerate oligonucleotide based on a sequence present in the effector domain of the Sec4 protein, Zahraoui et al. (1994) isolated a cDNA encoding RAB13. The predicted 203-amino acid protein has the typical structural features of Ras-related proteins, including a conserved GTP-binding site. RAB13 displays 61% and 56% amino acid identity with the human RAB8 (165040) and yeast Sec4 proteins, respectively. These proteins share a long conserved N-terminal region but have divergent C-terminal portions. Northern blot analysis showed that RAB13 is expressed as a 1.2-kb transcript in Caco-2 cells. Immunoblot analysis using antibodies against RAB13 detected a 24-kD protein in Caco-2 cell lysates. Immunofluorescence studies demonstrated that RAB13 colocalizes with the tight junction marker ZO1 (TJP1; 601009) in epithelial cells. In cells devoid of tight junctions, RAB13 associates with vesicles dispersed throughout the cytoplasm.
Leek et al. (1997) mapped the RAB13 gene to chromosome 12q13 by in situ hybridization. However, Gross (2011) mapped the RAB13 gene to chromosome 1q21.3 based on an alignment of the RAB13 sequence (GenBank BC073168) with the genomic sequence (GRCh37).
Gross, M. B. Personal Communication. Baltimore, Md. 2/17/2011.
Leek, J. P., Hamlin, P. J., Wilton, J., Lench, N. J. Assignment of the Rab13 gene (RAB13) to human chromosome band 12q13 by in situ hybridization. Cytogenet. Cell Genet. 79: 210-211, 1997. [PubMed: 9605854] [Full Text: https://doi.org/10.1159/000134724]
Novick, P., Zerial, M. The diversity of Rab proteins in vesicle transport. Curr. Opin. Cell Biol. 9: 496-504, 1997. [PubMed: 9261061] [Full Text: https://doi.org/10.1016/s0955-0674(97)80025-7]
Salminen, A., Novick, P. J. A ras-like protein is required for a post-Golgi event in yeast secretion. Cell 49: 527-538, 1987. [PubMed: 3552249] [Full Text: https://doi.org/10.1016/0092-8674(87)90455-7]
Zahraoui, A., Joberty, G., Arpin, M., Fontaine, J. J., Hellio, R., Tavitian, A., Louvard, D. A small rab GTPase is distributed in cytoplasmic vesicles in nonpolarized cells but colocalizes with the tight junction marker ZO-1 in polarized epithelial cells. J. Cell. Biol. 124: 101-115, 1994. [PubMed: 8294494] [Full Text: https://doi.org/10.1083/jcb.124.1.101]