High impact information on BOS1

• These vesicles contain Bos1p, Sec22p, and Ypt1p, but not Bet1p [1].
• Bos1p, an integral membrane protein of the endoplasmic reticulum to Golgi transport vesicles, is required for their fusion competence [1].
• The functional interactions of Bos1p with Ypt1p and Sec22p may be necessary for the fusion competence of the ER to Golgi transport vesicles [1].
• Other v-SNAREs, Sec22p and Ykt6p, might interact more weakly with the COPII coat or interact indirectly by binding to Bet1p or Bos1p [2].
• The BOS1 gene encodes an essential 27-kD putative membrane protein that is required for vesicular transport from the ER to the Golgi complex in yeast [3].

Biological context of BOS1

• DNA sequence analysis predicts that Bos1 is a 27-kD protein containing a putative membrane-spanning domain [3].
• The temperature-sensitive phenotype of the uso1-1 mutant can be suppressed by overexpression of each of the known ER to Golgi v-SNAREs (Bet1p, Bos1p, Sec22p, and Ykt6p) [4].
• Consistent with this proposal, we observe that the Yip1p.Yif1p complex binds to the ER to Golgi SNAREs Bos1p and Sec22p, two components of the membrane fusion machinery [5].

Anatomical context of BOS1

• Vesicles bearing mutations in Bet1p or Bos1p inhibit fusion with wild-type acceptor membranes, but acceptor membranes containing these mutations are fully functional [6].

Physical interactions of BOS1

• Bos1p co-purifies with the ER to Golgi transport vesicles and co-fractionates with Bet1p and the ER membrane [7].
• The synaptobrevin-related domains of Bos1p and Sec22p bind to the syntaxin-like region of Sed5p [8].

Regulatory relationships of BOS1

• Bet1p activates the v-SNARE Bos1p [9].

Other interactions of BOS1

• Here we report that regions of Bos1p and Sec22p, which are homologous to synaptobrevin, bind to the syntaxin-like domain of Sed5p [8].
• Complementation analysis revealed that sec32-1 is an allele of BOS1, a gene implicated in vesicle targeting to the Golgi complex, and sec33-1 is an allele of RET1, a gene that encodes the alpha subunit of coatomer [10].
• Unexpectedly, yeast strains lacking Vma21p fail to sort the endoplasmic reticulum to Golgi v-SNARE, Bos1p, efficiently into COPII vesicles, yet these vesicles are fully fusion competent [11].

Analytical, diagnostic and therapeutic context of BOS1

• The data obtained by monitoring of Kex2p cleavage, by immunofluorescence microscopy and cell fractionation showed that Bos1-alpha and Bet1-alpha have different cellular localization and dynamics [12].
• Quantitative Western blot analysis indicates that protein markers of cytosol and cellular membranes are depleted throughout the purification, whereas the synaptobrevin-like Bet1, Sec22, and Bos1 proteins are highly enriched [13].

References