Corratgé-Faillie Claire, Lacombe Benoît
Biochimie et Physiologie Moléculaire des Plantes, UMR CNRS/INRA/SupAgro/UM, Institut de Biologie Intégrative des Plantes "Claude Grignon"place Viala, 34060 Montpellier, France.
J Exp Bot. 2017 Jun 1;68(12):3107-3113. doi: 10.1093/jxb/erw499.
The conventional approach to categorizing transporters has been to class them according to their sequence homology, defining a 'family' (or a 'superfamily' if they are numerous), and according to their substrate specificity or selectivity. This general view is still relevant for some transporters, but it is being increasingly challenged. Here, we take the NRT1/PTR FAMILY (NPF) as one such example. NPF members do indeed display sequence and structural homologies with peptide transporter (PTR) proteins involved in the uptake of di- and tri-peptides in most other organisms. And in plants they were initially characterized as nitrate or peptide transporters. However, in recent years several other substrates have been identified, namely nitrite, chloride, glucosinolates, auxin (IAA), abscisic acid (ABA), jasmonates (JAs), and gibberellins (GAs). Some of these transporters are even capable of transporting more than one different substrate (e.g. nitrate/auxin, nitrate/ABA, nitrate/glucosinolates, or GA/JA). In this review, we give an overview of the substrate-specificity of the Arabidopsis NPF.
对转运蛋白进行分类的传统方法是根据它们的序列同源性进行归类，确定一个“家族”（如果数量众多则为“超家族”），并依据它们的底物特异性或选择性来划分。这种普遍观点对某些转运蛋白仍然适用，但正受到越来越多的挑战。在此，我们以NRT1/PTR家族（NPF）为例进行说明。NPF成员确实与大多数其他生物体中参与二肽和三肽摄取的肽转运蛋白（PTR）具有序列和结构同源性。在植物中，它们最初被鉴定为硝酸盐或肽转运蛋白。然而，近年来又发现了其他几种底物，即亚硝酸盐、氯离子、芥子油苷、生长素（IAA）、脱落酸（ABA）、茉莉酸（JAs）和赤霉素（GAs）。其中一些转运蛋白甚至能够转运不止一种不同的底物（例如硝酸盐/生长素、硝酸盐/ABA、硝酸盐/芥子油苷或GA/JA）。在本综述中，我们概述了拟南芥NPF的底物特异性。
