High impact information on VAM6

• The COOH-terminal 148 amino acids of Vps39 direct its association with the class C-Vps complex by binding to Vps11 [1].
• Like other VAM-encoded proteins, which are needed for homotypic vacuole fusion, we now report that Vam2p and its associated protein Vam6p/Vps39p are needed on each vacuole partner for homotypic fusion [2].
• We propose that the class C-Vps complex both promotes Vps39-dependent nucleotide exchange on Ypt7 and, based on the work of Price et al., acts as a Ypt7 effector that tethers transport vesicles to the vacuole [1].
• However, disruption of YDL077c (also known as VAM6) exhibited an slow growth phenotype in minimal media and also in rich media containing glycerol as a carbon source [3].
• We report here the identification and characterization of a novel protein in Aspergillus nidulans, AvaB, that exhibits similarity to Vam6p/Vps39p and plays a critical role in vacuolar morphogenesis in A. nidulans [4].

Biological context of VAM6

• It has been demonstrated that Saccharomyces cerevisiae Vam6p/Vps39p plays a critical role in the tethering steps of vacuolar membrane fusion by facilitating guanine nucleotide exchange on small guanosine triphosphatase (GTPase) Vam4p/Ypt7p [4].

Anatomical context of VAM6

• Deletion of the VAM2 and VAM6 functions resulted in accumulation of numerous vacuole-related structures of 200-400 nm in diameter that were much smaller than the normal vacuoles [5].

Analytical, diagnostic and therapeutic context of VAM6

• Molecular cloning and functional characterization of avaB, a gene encoding Vam6p/Vps39p-like protein in Aspergillus nidulans [4].

References