Graham L A, Stevens T H
Institute of Molecular Biology, University of Oregon, Eugene 97403-1229, USA.
J Bioenerg Biomembr. 1999 Feb;31(1):39-47. doi: 10.1023/a:1005455411918.
The yeast vacuolar proton-translocating ATPase (V-ATPase) is the best characterized member of the V-ATPase family. Biochemical and genetic screens led to the identification of a large number of genes in yeast, designated VMA, encoding proteins required to assemble a functional V-ATPase. A total of thirteen genes encode subunits of the final enzyme complex. In addition to subunit-encoding genes, we have identified three genes that code for proteins that are not part of the final V-ATPase complex yet required for its assembly. We refer to these nonsubunit Vma proteins as assembly factors, since their function is dedicated to assembling the V-ATPase. The assembly factors, Vma12p, Vma21p, and Vma22p are localized to the endoplasmic reticulum (ER) and aid the assembly of newly synthesized V-ATPase subunits that are translocated into the ER membrane. At least two of these proteins, Vma12p and Vma22p, function together in an assembly complex and interact directly with nascent V-ATPase subunits.
酵母液泡质子转运ATP酶（V-ATP酶）是V-ATP酶家族中特征最明确的成员。生化和遗传筛选导致在酵母中鉴定出大量名为VMA的基因，这些基因编码组装功能性V-ATP酶所需的蛋白质。共有13个基因编码最终酶复合物的亚基。除了亚基编码基因外，我们还鉴定出三个基因，它们编码的蛋白质不是最终V-ATP酶复合物的一部分，但却是其组装所必需的。我们将这些非亚基Vma蛋白称为组装因子，因为它们的功能专门用于组装V-ATP酶。组装因子Vma12p、Vma21p和Vma22p定位于内质网（ER），并协助新合成的V-ATP酶亚基组装到ER膜中。这些蛋白质中至少有两种，即Vma12p和Vma22p，在一个组装复合物中共同发挥作用，并直接与新生的V-ATP酶亚基相互作用。
