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Expression of protein‐tyrosine phosphatases in the major insulin target tissues
Author(s) -
Norris Kjeld,
Norris Fanny,
Kono Dwight H,
Vestergaard Henrik,
Pedersen Oluf,
Theofilopoulos Argyrios N,
Møller Niels Peter H
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)01133-2
Subject(s) - protein tyrosine phosphatase , skeletal muscle , insulin receptor , biology , phosphatase , western blot , microbiology and biotechnology , receptor tyrosine kinase , signal transduction , adipose tissue , northern blot , insulin , messenger rna , phosphorylation , biochemistry , endocrinology , gene , insulin resistance
Protein‐tyrosine phosphatases (PTPs) are key regulators of the insulin receptor signal transduction pathway. We have performed a detailed analysis of PTP expression in the major human insulin target tissues or cells (liver, adipose tissue, skeletal muscle and endothelial cells). To obtain a representative picture, all tissues were analyzed by PCR using three different primer sets corresponding to conserved regions of known PTPs. A total of 24 different PTPs were identified. A multiprobe RNase protection assay was developed to obtain a semi‐quantitative measure of the expression levels of selected PTPs. Surprisingly, PTP‐LAR, previously suggested to be a major regulator of the insulin receptor tyrosine kinase, was expressed in extremely low levels in skeletal muscle, whereas the related receptor‐type PTP‐σ and PTP‐α were expressed in relatively high levels in all four tissues. The low levels of LAR PTP mRNA in skeletal muscle were further confirmed by Northern blot analysis.