Rasooly Reuven, Balaban Naomi
Department of Nutrition, University of California, Davis, One Shields Ave, Meyer Hall Room 3135, Davis, CA 95616, USA.
Parasitol Res. 2002 Dec;88(12):1034-9. doi: 10.1007/s00436-002-0704-6. Epub 2002 Jul 31.
Trypanosomes are protozoan parasites, containing subpellicular microtubules that are crosslinked to one another and to the plasma membrane by unique microtubule associate proteins (MAPs). One of these MAPs, purified from the subpellicular microtubules by a tubulin affinity column, is termed p15alpha. This protein was shown to be specific to the subpellicular microtubules by immunoelectron microscopy and was also shown to induce microtubule bundling. We show here that the gene coding for p15alpha is present in multiple copies. It is 258 bp long and contains 16 highly organized 15 bp long repetitive sequences. The deduced amino acid sequence indicates that p15alpha contains 16 highly organized, nearly identical tandem repeats, with a periodicity of five amino acids, which are rich in positively charged and in non-polar (hydrophobic) amino acids. The p15 family is unique to trypanosomes and has no significant sequence homology to other species. p15 can bind both tubulin and phospholipids in vitro and is therefore hypothesized to contribute to the stability of the trypanosome subpellicular microtubules.
锥虫是原生动物寄生虫，含有皮下微管，这些微管通过独特的微管相关蛋白（MAPs）相互交联并与质膜交联。其中一种从皮下微管通过微管蛋白亲和柱纯化的MAPs被称为p15α。通过免疫电子显微镜显示该蛋白对皮下微管具有特异性，并且还显示出诱导微管成束。我们在此表明，编码p15α的基因以多个拷贝存在。它长258 bp，包含16个高度组织化的15 bp长的重复序列。推导的氨基酸序列表明，p15α包含16个高度组织化、几乎相同的串联重复序列，具有五个氨基酸的周期性，富含带正电荷和非极性（疏水）氨基酸。p15家族是锥虫特有的，与其他物种没有明显的序列同源性。p15在体外可以结合微管蛋白和磷脂，因此推测它有助于锥虫皮下微管的稳定性。
