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PKC‐dependent phosphorylation of the p97 repressor regulates the transcription of aldolase A L‐type promoter
Author(s) -
Costanzo Paola,
Lupo Angelo,
Medugno Lina,
D'Agostino Paola,
Zevino Chiara,
Izzo Paola
Publication year - 1999
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(99)00775-9
Subject(s) - repressor , dephosphorylation , transcription (linguistics) , microbiology and biotechnology , phosphorylation , aldolase a , transcription factor , biology , chemistry , biochemistry , phosphatase , enzyme , gene , linguistics , philosophy
Expression of mouse aldolase A L‐type mRNA is negatively modulated by a cis element (AldA‐NRE), located within the aldolase A distal promoter (pL). AldA‐NRE interacts with a 97‐kDa repressor protein (p97), which binds DNA in a cell cycle‐dependent manner. We demonstrate that the binding between AldA‐NRE and p97 decreases during differentiation of human Caco‐2 cells and is inversely correlated with L‐type mRNA expression. Phosphorylation of the p97 repressor weakened its DNA binding activity in differentiated Caco‐2 cells, while dephosphorylation enhanced the binding in proliferating cells. Stimulation of protein kinase C (PKC) in vivo decreased the binding of p97 to AldA‐NRE and stimulated transcription, while inhibition of PKC stimulated p97 binding and downregulated transcription. These findings suggest that PKC is a mediator of the binding and silencing function of the p97/AldA‐NRE repressor complex.