Dibbayawan T P, Harper J D, Elliott J E, Gunning B E, Marc J
School of Biological Sciences, University of Sydney, Australia.
Cell Biol Int. 1995 Jul;19(7):559-67. doi: 10.1006/cbir.1995.1102.
gamma-Tubulin is a putative component of microtubule initiating material. To further explore its subcellular distribution in plant and animal cells, we have raised a polyclonal antibody, Rb27, directed towards a conserved region (EEFATEGTDRKDVFFY) of the gamma-tubulin molecule. Immunoblotting of cell protein extracts with Rb27 reveals a polypeptide band of M(r) 49 kD in HeLa and a 58 kD band in Chlamydomonas. Although these polypeptides are comparable in size to forms of gamma-tubulin detected previously in mammalian and plant protein extracts by other antibodies to gamma-tubulin, by immunofluorescence microscopy Rb27 gives localization patterns not previously seen. It localizes specifically with the centrioles in HeLa cells and with the basal body complex in Chlamydomonas. Other gamma-tubulin antibodies label pericentriolar material. Because of the similarities in the size of the polypeptides recognized by our and other gamma-tubulin antibodies, and a restricted co-localization with known microtubule-organizing centres in evolutionarily distant organisms, we propose that Rb27 recognizes a novel conserved gamma-tubulin isotype.
γ-微管蛋白是微管起始物质的一种假定成分。为了进一步探究其在植物和动物细胞中的亚细胞分布，我们制备了一种针对γ-微管蛋白分子保守区域（EEFATEGTDRKDVFFY）的多克隆抗体Rb27。用Rb27对细胞蛋白提取物进行免疫印迹分析，结果显示在HeLa细胞中出现一条分子量为49 kD的多肽条带，在衣藻中出现一条58 kD的条带。尽管这些多肽的大小与之前其他γ-微管蛋白抗体在哺乳动物和植物蛋白提取物中检测到的γ-微管蛋白形式相当，但通过免疫荧光显微镜观察，Rb27呈现出以前未见的定位模式。它在HeLa细胞中特异性地定位于中心粒，在衣藻中定位于基体复合体。其他γ-微管蛋白抗体标记中心粒周围物质。鉴于我们的抗体和其他γ-微管蛋白抗体所识别的多肽大小相似，且在进化上距离较远的生物体中与已知微管组织中心存在有限的共定位，我们提出Rb27识别一种新的保守γ-微管蛋白同种型。
