TY  - JOUR
A1  - Cismasiu, Valeriu B.
A1  - Denes, Stefan A.
A1  - Reiländer, Helmut
A1  - Michel, Hartmut
A1  - Szedlacsek, Stefan E.
T1  - The MAM (meprin/A5-protein/PTPmu) domain is a homophilic binding site promoting the lateral dimerization of receptor-like protein-tyrosine phosphatase μ
T2  - Journal of biological chemistry
N2  - The MAM (meprin/A5-protein/PTPmu) domain is present in numerous proteins with diverse functions. PTPμ belongs to the MAM-containing subclass of protein-tyrosine phosphatases (PTP) able to promote cell-to-cell adhesion. Here we provide experimental evidence that the MAM domain is a homophilic binding site of PTPμ. We demonstrate that the MAM domain forms oligomers in solution and binds to the PTPμ ectodomain at the cell surface. The presence of two disulfide bridges in the MAM molecule was evidenced and their integrity was found to be essential for MAM homophilic interaction. Our data also indicate that PTPμ ectodomain forms oligomers and mediates the cellular adhesion, even in the absence of MAM domain homophilic binding. Reciprocally, MAM is able to interact homophilically in the absence of ectodomain trans binding. The MAM domain therefore contains independent cis and trans interaction sites and we predict that its main role is to promote lateral dimerization of PTPμ at the cell surface. This finding contributes to the understanding of the signal transduction mechanism in MAM-containing PTPs.
Y1  - 2004
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/76167
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-761677
SN  - 0021-9258
VL  - 279.2004
IS  - 26
SP  - 26922
EP  - 26931
PB  - Elsevier
CY  - Amsterdam
ER  -