Open AccessPhosphorylation and Dephosphorylation in the Proline‐Rich C‐Terminal Domain of Microtubule‐Associated Protein 2
Author(s) -
Sánchez Carlos,
Tompa Peter,
Szücs Kornélia,
Friedrich Peter,
Avila Jesús
Publication year - 1996
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1996.00765.x
Subject(s) - phosphorylation , kinase , dephosphorylation , biology , biochemistry , phosphatase , gsk 3 , protein phosphorylation , protein phosphatase 1 , microbiology and biotechnology , protein kinase a
The C‐terminal domain of microtubule‐associated protein 2 (MAP2) contains a proline‐rich region and the tubulin‐binding domain. We have generated antibodies to follow the phosphorylation state of the proline‐rich domain. One of these antibodies (no. 305) has been raised against a synthetic peptide P (sequence RTPGTPGTPSY) phosphorylated at the threonine residues. This sequence is present in the proline‐rich region of MAP2 and is phosphorylated in vitro by at least three different proline‐directed protein kinases: p42 mpk , p34 cdc2 , and GSK3 (glycogen‐synthase kinase 3) α/β The MAP2 sites phosphorylated by these kinases are different, although all of them phosphorylate the C‐terminal domain of MAP2 as determined by Staphylococcus aureus V8 protease mapping. Nonphosphorylated peptide P can be phosphorylated in vitro by all three kinases studied with similar efficiency. In high‐molecular‐mass MAP2, this sequence is highly phosphorylated in vivo at the late stages of rat development. This motif can be rapidly dephosphorylated in vitro by protein‐phosphatase 1 (PP1) and 2A (PP2A) catalytic subunits but not by PP2B.