High impact information on NYV1

• Homotypic vacuole fusion requires many membrane proteins, including the Ypt7p guanosine triphosphatase and a "SNARE complex" with Vam3p and Nyv1p [1].
• In 'bypass fusion', without ATP but with added rVam7p, there are sufficient unpaired vacuolar SNAREs Vam3p, Vti1p, and Nyv1p to interact with Vam7p and support fusion [2].
• High concentrations of rVam7p allow the R-SNARE Ykt6p to substitute for Nyv1p for fusion; this functional redundancy among vacuole SNAREs may explain why nyv1delta strains lack the vacuole fragmentation seen with mutants in other fusion catalysts [2].
• The Vtc complex associates with the R-SNARE Nyv1p and with V(0) [3].
• A YXXPhi-like adaptin-dependent sorting signal (Y(31)GTI(34)) unique to the longin domain of Nyv1p mediates interactions with the AP3 complex in vivo and in vitro [4].

Biological context of NYV1

• We show that amino acid substitutions to Y(31)GTI(34) (Y31Q;I34Q) resulted in mislocalization of Nyv1p as well as reduced binding of the mutant protein to the AP3 complex [4].
• Development of a semi-quantitative plate-based alpha-galactosidase gene reporter for Schizosaccharomyces pombe and its use to isolate a constitutively active Mam2 [5].

Anatomical context of NYV1

• Vacuole SNAREs, including the t-SNAREs Vam3p and Vam7p and the v-SNARE Nyv1p, are found in a multisubunit "cis" complex on isolated organelles [6].
• Aut7p interacts physically with the following two v-SNAREs: Bet1p, which is involved in endoplasmic reticulum to Golgi vesicular transport, and Nyv1p, implicated in vacuolar inheritance [7].
• The vacuolar SNAREs Nyv1p and Vam3p avoid this fate by using the AP-3-dependent pathway, which bypasses late endosomes, but the endosomal SNARE Pep12p must avoid it more directly [8].

Associations of NYV1 with chemical compounds

• Identification of the Yeast R-SNARE Nyv1p as a Novel Longin Domain-containing Protein [4].
• We conclude that Nyv1p can interact physically with Pmc1p and inhibit its Ca(2+) transport activity in the vacuole membrane [9].
• Vacuoles in Acb1p-depleted cells are multi-lobed, contain significantly less of the SNAREs (soluble N -ethylmaleimide-sensitive fusion protein attachment protein receptors) Nyv1p, Vam3p and Vti1p, and are unable to fuse in vitro [10].

Other interactions of NYV1

• Even in the absence of the vacuolar v-SNARE Nyv1p, a subcomplex which includes Vam7p and the t-SNARE Vam3p is preserved [11].
• Inhibition of the Ca(2+)-ATPase Pmc1p by the v-SNARE protein Nyv1p [9].
• We speculate that during vacuole fusion, Nyv1 is the classical R-SNARE, whereas the Ykt6-containing complex has a novel function in Vac8 palmitoylation [12].
• Although the sorting of Nyv1p to the limiting membrane of the vacuole is dependent upon the Y(31)GTI(34) motif, and Y31 in particular, our findings with structure-based amino acid substitutions in the mu chain (Apm3p) of yeast AP3 suggest a mechanistically distinct role for this subunit in the recognition of YXXPhi-like sorting signals [4].

References