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Proteolytic processing of the receptor‐type protein tyrosine phosphatase PTPBR7
Author(s) -
Dilaver Gönül,
van de Vorstenbosch Rinske,
Tárrega Céline,
Ríos Pablo,
Pulido Rafael,
van Aerde Karlijn,
Fransen Jack,
Hendriks Wiljan
Publication year - 2007
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2006.05568.x
Subject(s) - ectodomain , gene isoform , protein tyrosine phosphatase , alternative splicing , transmembrane protein , biology , tyrosine , biochemistry , microbiology and biotechnology , transmembrane domain , tyrosine phosphorylation , amino acid , receptor , gene
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, PTPPBSγ42 and PTPPBSγ37, 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.