Sze H, Ward JM, Lai S, Perera I
J Exp Biol. 1992 Nov 1;172(Pt 1):123-135. doi: 10.1242/jeb.172.1.123.
Acidification of endomembrane compartments by the vacuolar-type H+-translocating ATPase (V-ATPase) is vital to the growth and development of plants. The V-ATPase purified from oat roots is a large complex of 650x10(3 )Mr that contains 10 different subunits of 70, 60, 44, 42, 36, 32, 29, 16, 13 and 12x10(3 )Mr. This set of ten polypeptides is sufficient to couple ATP hydrolysis to proton pumping after reconstitution of the ATPase into liposomes. Unlike some animal V-ATPases, the purified and reconstituted V-ATPase from oat is directly stimulated by Cl-. The peripheral complex of the ATPase includes the nucleotide-binding subunits of 70 and 60x10(3 )Mr and polypeptides of 44, 42, 36 and 29x10(3 )Mr. Six copies of the 16x10(3 )Mr proteolipid together with three other polypeptides are thought to make up the integral sector that forms the H+-conducting pathway. Release of the peripheral complex from the native membrane completely inactivates the pump; however, the peripheral subunits can be reassembled with the membrane sector to form a functional H+ pump. Comparison of V-ATPases from several plants indicates considerable variations in subunit composition. Hence, several forms of the V-ATPase may exist among, and probably within, plant species. At least four distinct cDNAs encode the 16x10(3 )Mr proteolipid subunit in oat. Multiple genes could encode different subtypes of the H+ pump that are regulated by the developmental stage and physiological function specific to the cell or tissue type.
液泡型H⁺转运ATP酶（V-ATP酶）介导的内膜区室酸化对植物的生长发育至关重要。从燕麦根中纯化得到的V-ATP酶是一种分子量为650×10³ Mr的大型复合物，包含10种不同亚基，分子量分别为70、60、44、42、36、32、29、16、13和12×10³ Mr。将该ATP酶重组到脂质体中后，这一组十种多肽足以将ATP水解与质子泵浦偶联起来。与一些动物V-ATP酶不同，从燕麦中纯化并重组的V-ATP酶受到Cl⁻的直接刺激。该ATP酶的外周复合物包括分子量为70和60×10³ Mr的核苷酸结合亚基以及分子量为44、42、36和29×10³ Mr的多肽。六个分子量为16×10³ Mr的质子脂质体亚基与其他三种多肽共同构成了形成H⁺传导途径的整合区。外周复合物从天然膜上释放会使泵完全失活；然而，外周亚基可以与膜区重新组装形成功能性H⁺泵。对几种植物的V-ATP酶进行比较表明，亚基组成存在相当大的差异。因此，在植物物种之间以及可能在物种内部可能存在多种形式的V-ATP酶。在燕麦中，至少有四个不同的cDNA编码分子量为16×10³ Mr的质子脂质体亚基。多个基因可能编码H⁺泵的不同亚型，这些亚型受细胞或组织类型特有的发育阶段和生理功能调控。
