Proteolytic processing of the receptor-type protein tyrosine phosphatase PTPBR7
Proteolytic processing of the receptor-type protein tyrosine phosphatase PTPBR7
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DOI：
10.1111/j.1742-4658.2006.05568.x
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发表时间：
2007-01-01
期刊：
影响因子：
5.4
通讯作者：
Hendriks, Wiljan
中科院分区：
文献类型：
--
作者：
Dilaver, Gonul;de Vorstenbosch, Rinske van;Hendriks, Wiljan
单拷贝小鼠基因Ptprr通过使用不同的启动子、选择性剪接和多个翻译起始位点在神经元细胞中产生不同的蛋白酪氨酸磷酸酶（PTP）亚型。在这里，我们研究了一系列的翻译后修饰施加在PTPRR蛋白亚型PTPBR 7，PTP-SL，PTPPBS γ 42和PTPPBS γ 37，具有不同的N-末端片段和本地化的不同部分的细胞。所有的异构体被发现是短暂的，组成性磷酸化的蛋白质。此外，跨膜同种型PTPBR 7在氨基酸位置136和137之间进行N-末端蛋白水解加工，产生另外的65-kDa跨膜PTPRR同种型。与其他一些受体型PTP不同，蛋白水解产生的N-末端胞外域不与该PTPRR-65保持结合。PTPBR 7衍生多肽在细胞表面的脱落进一步增加了PTPRR生物学的分子复杂性。
The single-copy mouse gene Ptprr gives rise to different protein tyrosine phosphatase (PTP) isoforms in neuronal cells through the use of distinct promoters, alternative splicing, and multiple translation initiation sites. Here, we examined the array of post-translational modifications imposed on the PTPRR protein isoforms PTPBR7, PTP-SL, PTPPBS gamma 42 and PTPPBS gamma 37, which have distinct N-terminal segments and localize to different parts of the cell. All isoforms were found to be short-lived, constitutively phosphorylated proteins. In addition, the transmembrane isoform, PTPBR7, was subject to N-terminal proteolytic processing, in between amino acid position 136 and 137, resulting in an additional, 65-kDa transmembrane PTPRR isoform. Unlike for some other receptor-type PTPs, the proteolytically produced N-terminal ectodomain does not remain associated with this PTPRR-65. Shedding of PTPBR7-derived polypeptides at the cell surface further adds to the molecular complexity of PTPRR biology.