HGNC Approved Gene Symbol: STX7
Cytogenetic location: 6q23.2 Genomic coordinates (GRCh38) : 6:132,445,867-132,513,472 (from NCBI)
In the cell, the specificity of vesicle transport is thought to occur through the interaction of vesicle proteins with receptors such as syntaxins on a particular target membrane. See alpha-SNAP (603215). Pep12p, or Vps6p, is a syntaxin identified in S. cerevisiae and in Arabidopsis that is required for the sorting of soluble hydrolases from the Golgi complex to the vacuole. By searching an EST database for human homologs of Pep12p, Wang et al. (1997) identified partial syntaxin-7 (STX7) cDNAs. Using a partial cDNA as a probe, they isolated a fetal brain cDNA corresponding to the entire coding region of syntaxin-7. The deduced 261-amino acid STX7 protein contains a putative C-terminal transmembrane domain and 3 coiled-coil domains. The human protein shares 34% and 25% sequence identity with Arabidopsis and yeast Pep12p, respectively. In vitro, recombinant protein bound specifically to alpha-SNAP, a key regulator of transport vesicle fusion at multiple stages of the secretory pathway. Northern blot analysis revealed that syntaxin-7 was expressed as 1.8- and 3.6-kb mRNAs in all tissues tested.
Using immunocytochemistry, fluorescence, and confocal microscopy, Collins et al. (2002) showed that STX7 and STX13 (STX12; 606892) are involved in the ordered fusion of endosomes and lysosomes with the phagosome, where phagocytic cells kill and degrade internalized foreign particles. STX12 is localized to the recycling endosome compartment, whereas STX7 is found in late endosomes and lysosomes and both are recruited to the phagosome. However, STX12 is acquired earlier before rapidly recycling off the phagosome, whereas STX7 is recruited later and continues to accumulate throughout the phagosome maturation process.
By analysis of a human monochromosomal panel, Wang et al. (1997) mapped the STX7 gene to chromosome 6.
Collins, R. F., Schreiber, A. D., Grinstein, S., Trimble, W. S. Syntaxins 13 and 7 function at distinct steps during phagocytosis. J. Immun. 169: 3250-3256, 2002. [PubMed: 12218144] [Full Text: https://doi.org/10.4049/jimmunol.169.6.3250]
Wang, H., Frelin, L., Pevsner, J. Human syntaxin 7: a Pep12p/Vps6p homologue implicated in vesicle trafficking to lysosomes. Gene 199: 39-48, 1997. [PubMed: 9358037] [Full Text: https://doi.org/10.1016/s0378-1119(97)00343-0]