High impact information on YPT32

• First, YPT31/YPT32 suppress the sec2-78 mutation [1].
• Ypt32 recruits the Sec4p guanine nucleotide exchange factor, Sec2p, to secretory vesicles; evidence for a Rab cascade in yeast [1].
• Cells deleted for the YPT31 gene and carrying a conditional ypt32 mutation exhibit protein transport defects in the late exocytic pathway, but not in vacuolar protein sorting [2].
• Bioinformatic and comparative localization of rab proteins reveals functional insights into the uncharacterized GTPases ypt10p and ypt11p [3].
• Gyp1p also stimulated the GTPase activity of several other yeast Rab proteins including Ypt1p, Ypt7p, and Ypt51p but showed no GAP activity on Ypt6p and Ypt32p [4].

Biological context of YPT32

• Here we report that mutant alleles of YPT31 and YPT32, whose gene products have a reduced affinity for GTP, are able to suppress the dominant lethal phenotype of YPT1(N121I) [5].

Anatomical context of YPT32

• In yeast, Ypt1p has an essential function late in endoplasmic reticulum (ER) to Golgi transport, and the redundant Ypt31/Ypt32 GTPases have been proposed to act in transport through and/or from the Golgi [5].
• From the phenotypic alterations observed in ypt31 and ypt32 mutants, it seems likely that the two GTPases are involved in intra-Golgi transport or in the formation of transport vesicles at the most distal Golgi compartment [6].
• Ypt32p regulates the translocation of Chs3p from an internal pool to the plasma membrane [7].
• In these mutants, Sec2p accumulates in the cytosol in a complex with the exocyst and is not recruited to vesicles by Ypt32p [8].

Other interactions of YPT32

• Yeast cells can tolerate deletion of either the YPT31 or the YPT32 gene, but not both [2].
• YPT31 and YPT32, the multi-copy suppressors of the trs130(ts1) mutant, differed in the extent of suppression of the mutant phenotypes and in their genetic interaction with TRS130 [9].
• We propose that Mlc1p/Myo2p interaction is stimulated by a signal that requires Sec2p and activation of Ypt32p [10].
• Either gain of Ypt32p function, by overexpression, or loss-of-function mutations alter the localization of Chs3p-GFP [7].
• Moreover, cells overexpressing Ypt32p accumulate chitin at the cell surface independent of Chs5p [7].

References