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Transmembrane homodimerization of receptor‐like protein tyrosine phosphatases
Author(s) -
Chin Chen-Ni,
Sachs Jonathan N.,
Engelman Donald M.
Publication year - 2005
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/j.febslet.2005.05.071
Subject(s) - protein tyrosine phosphatase , transmembrane protein , membrane protein , chemistry , microbiology and biotechnology , phosphatase , tyrosine , biochemistry , receptor tyrosine kinase , integral membrane protein , transmembrane domain , receptor , membrane , biology , phosphorylation
Receptor‐like protein tyrosine phosphatases (RPTPs) are type I integral membrane proteins. Together with protein tyrosine kinases, RPTPs regulate the phosphotyrosine levels in the cell. Studies of two RPTPs, CD45 and PTPα, have provided strong evidence that dimerization leads to inactivation of the receptors, and that the dimerization of PTPα involves interactions in the transmembrane domain (TMD). Using the TOXCAT assay, a genetic approach for analyzing TM interactions in Escherichia coli membranes, we show that the TMD of RPTPs interact in the membrane, albeit to different extents. Using fusion proteins of TMDs, we also observe an equilibrium between monomer and dimer in sodium dodecyl sulfate (SDS) micelles. Through a mutational study of the DEP1 TMD, we demonstrate that these interactions are specific. Taken together, our results define a subset of the RPTP family in which TM homodimerization may act as a mediator of protein function.