Holocarboxylase synthetase: Correlation of protein localisation with biological function
Holocarboxylase synthetase: Correlation of protein localisation with biological function
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DOI：
10.1016/j.abb.2010.01.015
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发表时间：
2010-04-01
影响因子：
3.9
通讯作者：
Polyak, S. W.
中科院分区：
文献类型：
--
作者：
Bailey, L. M.;Wallace, J. C.;Polyak, S. W.
全新羧化酶合成酶（HCS）控制着必需微量营养素生物素（维生素H或B7）的细胞命运。HCS负责将生物素附着到存在于细胞质和线粒体中的生物素依赖酶上。另一种作用的证据，即基因表达的调节，也有报道。最近的免疫组织化学研究报告HCS主要是核，与HCS活性的位置不一致。提高对生物素生物学的理解需要对HCS有更多的了解。在这里，我们研究了HCS及其异构体的定位。在n端观察到三种不同的变体。所有HCS异构体主要是非核的，与生物素蛋白连接酶活性的分布一致。与较长的结构不同，Met（58）异构体在细胞核中也被检测到，这是一个新的观察结果，表明细胞核和细胞质之间有穿梭活动。我们解决了先前文献中的争议是由于使用部分纯化抗体时产生的特异性和检测限制。英国皇家版权所有(C) 2010出版的爱思唯尔公司。版权所有。
Holocarboxylase synthetase (HCS) governs the cellular fate of the essential micronutrient biotin (Vitamin H or B7). HCS is responsible for attaching biotin onto the biotin-dependent enzymes that reside in the cytoplasm and mitochondria. Evidence for an alternative role, viz the regulation of gene expression, has also been reported. Recent immunohistochemical studies reported HCS is primarily nuclear, inconsistent with the location of HCS activity. Improved understanding of biotin biology demands greater knowledge about HCS. Here, we investigated the localisation of HCS and its isoforms. Three variants were observed that differ at the N-terminus. All HCS isoforms were predominantly non-nuclear, consistent with the distribution of biotin protein ligase activity. Unlike the longer constructs, the Met(58) isoform was also detected in the nucleus - a novel observation suggesting shuttling activity between nucleus and cytoplasm. We resolved that the previous controversies in the literature are due to specificity and detection limitations that arise when using partially purified antibodies. Crown Copyright (C) 2010 Published by Elsevier Inc. All rights reserved.