TY - JOUR
T1 - Contributions of the mitogen-activated protein (MAP) kinase backbone and phosphorylation loop to MEK specificity
AU - Robinson, Megan J.
AU - Cheng, Mangeng
AU - Khokhlatchev, Andrei
AU - Ebert, Doug
AU - Ahn, Natalie
AU - Guan, Kun Liang
AU - Stein, Bernd
AU - Goldsmith, Elizabeth
AU - Cobb, Melanie H.
PY - 1996
Y1 - 1996
N2 - To examine the specificity of MEKs for MAP kinase family members, we determined the abilities of several MEK isoforms to phosphorylate mutants of the MAP kinase ERK2 and the related kinase ERK3 which are modified in the phosphorylation loop. The ERK2 mutants included mutations of the two phosphorylation sites, mutations of the acidic residue between these two sites, and mutations that shorten the length of this loop. All mutants were tested for phosphorylation by six mammalian MEKs and compared with several wild type MAP kinases. MEK1 and MEK2 phosphorylate a majority of the ERK2 mutants. MEK2 but not MEK1 will phosphorylate ERK3. Alteration of the residue between the two phosphorylation sites neither dramatically affected the activity of MEK1 and MEK2 toward ERK2 nor conferred recognition by other MEKs. Likewise, reduction of the length of the phosphorylation loop only partially reduces recognition by MEK1 and MEK2 but does not promote recognition by other MEKs. Thus other yet to be identified factors must contribute to the specificity of MEK recognition of MAP kinases.
AB - To examine the specificity of MEKs for MAP kinase family members, we determined the abilities of several MEK isoforms to phosphorylate mutants of the MAP kinase ERK2 and the related kinase ERK3 which are modified in the phosphorylation loop. The ERK2 mutants included mutations of the two phosphorylation sites, mutations of the acidic residue between these two sites, and mutations that shorten the length of this loop. All mutants were tested for phosphorylation by six mammalian MEKs and compared with several wild type MAP kinases. MEK1 and MEK2 phosphorylate a majority of the ERK2 mutants. MEK2 but not MEK1 will phosphorylate ERK3. Alteration of the residue between the two phosphorylation sites neither dramatically affected the activity of MEK1 and MEK2 toward ERK2 nor conferred recognition by other MEKs. Likewise, reduction of the length of the phosphorylation loop only partially reduces recognition by MEK1 and MEK2 but does not promote recognition by other MEKs. Thus other yet to be identified factors must contribute to the specificity of MEK recognition of MAP kinases.
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U2 - 10.1074/jbc.271.47.29734
DO - 10.1074/jbc.271.47.29734
M3 - Article
C2 - 8939908
AN - SCOPUS:0029909553
SN - 0021-9258
VL - 271
SP - 29734
EP - 29739
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 47
ER -