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Activation of the rat dopamine D2 receptor promoter by mitogen‐activated protein kinase and Ca 2+ /calmodulin‐dependent protein kinase II pathways
Author(s) -
Takeuchi Yusuke,
Miyamoto Eishichi,
Fukunaga Kohji
Publication year - 2002
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2002.01180.x
Subject(s) - map kinase kinase kinase , microbiology and biotechnology , protein kinase a , ask1 , mitogen activated protein kinase kinase , kinase , chemistry , cyclin dependent kinase 2 , mapk/erk pathway , biology
To investigate regulation of D2 receptor (D2R) gene expression by protein kinases, we evaluated effects of constitutively active MAPK kinase kinase (MEKK), Ca 2+ /calmodulin‐dependent protein kinase (CaMK) II, CaMKIV and cyclic AMP‐dependent protein kinase (PKA) on D2R promoter activity using luciferase reporter gene assays. A 1.5‐kbp fragment containing the rat D2R promoter was cloned upstream of the reporter and transfected into D2R‐expressing NB2A cells or nonexpressing NG108‐15 and C6 glioma cells. MEKK and CaMKII, but not CaMKIV and PKA, increased promoter activity 4.5‐ and 1.5‐fold, respectively, in NB2A cells. Inhibitory effects of a MEK inhibitor and lack of effect by dominant negative (DN)‐JNK1 or DN‐p38MAPK revealed that ERK but not JNK and p38MAPK is involved in MEKK‐induced promoter activation. Deletion and mutation of the promoter revealed that the MEKK‐responsive region was Sp1 site B between nucleotides −56 and −47. Overexpression of Sp1 suppressed promoter activity without affecting MEKK‐induced activation. Interestingly, overexpression of Zif268 increased promoter activity through the region between nucleotides −56 and −36. Increased activity by Zif268 was additive with CaMKII‐induced activation but not with activation induced by MEKK. Co‐transfection with CaMKII stimulated nuclear translocation of Zif268. These results suggest that ERK and CaMKII positively regulate the D2R promoter and that Zif268 is a potential transcription factor for the CaMKII‐dependent pathway.