Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland.
Essays Biochem. 2011 Sep 7;50(1):145-60. doi: 10.1042/bse0500145.
ABC (ATP-binding cassette) proteins are ubiquitously found in prokaryotes and eukaryotes and generally serve as membrane-intrinsic primary active pumps. In higher plants, ABC proteins constitute a large family, grouped phylogenetically into eight clusters, subfamilies ABCA-ABCI (ABCH is not found in plants). ABC transporters shuttle substrates as diverse as lipids, phytohormones, carboxylates, heavy metals, chlorophyll catabolites and xenobiotic conjugates across a variety of biological membranes. To date, the largest proportions of characterized members have been localized to the plasma membrane and the tonoplast, with dominant implications in cellular secretion and vacuolar sequestration, but they are also found in mitochondrial, plastidal and peroxisomal membranes. Originally identified as tonoplast-intrinsic proteins that shuttle xenobiotic conjugates from the cytosol into the vacuole, thus being an integral part of the detoxification machinery, ABC transporters are now recognized to participate in a multitude of physiological processes that allow the plant to adapt to changing environments and cope with biotic and abiotic stresses.
ABC（ATP 结合盒）蛋白广泛存在于原核生物和真核生物中，通常作为膜内在的初级主动泵。在高等植物中，ABC 蛋白构成一个大家族，系统发生上分为八个簇，亚家族 ABCA-ABCI（ABCH 在植物中不存在）。ABC 转运蛋白将各种底物如脂质、植物激素、羧酸、重金属、叶绿素分解产物和外源共轭物穿梭穿过各种生物膜。迄今为止，已鉴定出的大多数特征成员被定位到质膜和液泡膜，在细胞分泌和液泡隔离中起主要作用，但它们也存在于线粒体、质体和过氧化物酶体膜中。ABC 转运蛋白最初被鉴定为液泡内在蛋白，可将外源共轭物从细胞质穿梭到液泡中，从而成为解毒机制的一个组成部分，现在被认为参与了多种生理过程，使植物能够适应不断变化的环境并应对生物和非生物胁迫。
