High impact information on MSB3

• Cells lacking the GAP activity of Msb3p and Msb4p displayed secretory defects, including the accumulation of vesicles of 80-100 nm in diameter [1].
• Regulation of cell polarity by interactions of Msb3 and Msb4 with Cdc42 and polarisome components [2].
• Spa2 is required for the polarized localization of Msb3 and Msb4 at the bud tip [2].
• To further understand the biochemical function of Tre2 oncogene, we expressed its cDNA and, as a control, the RN-tre cDNA, in an msb3 msb4 double mutant yeast strain [3].
• Co-deletion of the MSB3 and MSB4 coding regions affects bipolar budding and perturbs the organization of the actin cytoskeleton [4].

Biological context of MSB3

• Deletion of either MSB3 or MSB4 alone did not produce any obvious phenotype, and the msb3 msb4 double mutant was viable [5].
• Co-deletion of the MSB3 and MSB4 coding regions caused growth inhibition in the presence of 10 mM caffeine and 4% dimethyl sulphoxide (DMSO), increased the sensitivity of the yeast strain to latrunculin-A, produced a random budding pattern in diploid cells, and affected the organization of the actin cytoskeleton [4].
• To find cell components that interact genetically with the products of the MSB3 and MSB4 genes, we screened a genomic library for multicopy suppressor genes restoring normal growth of the double mutant in the presence of DMSO and caffeine [6].
• We show here that Msb3p and Msb4p regulate exocytosis by functioning as GAPs for Sec4p in vivo [1].
• The yeast proteins Msb3p and Msb4p are two Ypt/Rab-specific GTPase-activating proteins (GAPs) involved in cell growth polarization [3].

Associations of MSB3 with chemical compounds

• The msb3 msb4 mutant's increased sensitivity to latrunculin-A suggests that the double mutation causes destabilization of the actin cytoskeleton [4].
• The msb3 msb4 yeast double mutation causes growth inhibition in the presence of DMSO and/or caffeine, affects the organization of the actin cytoskeleton, produces a random budding pattern in diploid cells, and affects segregation of the nucleus [6].

References