title: Activation of cAMP-response element-binding protein is positively regulated by PKA and calcium-sensitive calcineurin and negatively by PKC in insect.
abstract: The cAMP response element binding protein, CREB, is a G protein-coupled receptor (GPCR) signal-activated transcription factor implicated in the control of many biological processes. In the current study, we constructed a cAMP response element (CRE)-driven luciferase assay system for GPCR characterization in insect cells. Our results indicated that Gs-coupled Bombyx adipokinetic hormone receptor (AKHR) and corazonin receptor could effectively initiate CRE-driven luciferase transcription, but forskolin, a reagent widely used to activate adenylyl cyclase in mammalian systems, failed to induce luciferase activity in insect cells co-transfected with a CRE-driven reporter construct upon agonist treatment. Further investigation revealed that the specific protein kinase C (PKC) inhibitors exhibited stimulatory effects on CRE-driven reporter transcription, and blockage of Ca(2+) signals and inhibition of Ca(2+)-dependent calcineurin resulted in a significant decrease in the luciferase activity. Taken together, these results suggest that PKC likely acts as a negative regulator to modulate CREB activation; in contrast, Ca(2+) signals and Ca(2+)-dependent calcineurin, in addition to PKA, essentially contribute to the positive regulation of CREB activity. This study presents evidence to elucidate the underlying molecular mechanism by which CREB activation is regulated in insects.
authors.affiliation: Institute of Biochemistry, College of Life Science, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China.
authors.forename: Huipeng
authors.initials: H
authors.lastname: Yang
authors.forename: Xiaobai
authors.initials: X
authors.lastname: He
authors.forename: Jingwen
authors.initials: J
authors.lastname: Yang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Deng
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liao
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Chenggang
authors.initials: C
authors.lastname: Zhu
authors.forename: Ying
authors.initials: Y
authors.lastname: Shi
authors.forename: Naiming
authors.initials: N
authors.lastname: Zhou
mesh_terms: D000818:Animals; D012831:Bombyx / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D019703:Calcineurin / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics* / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D019476:Insect Proteins; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D019703:Calcineurin; D002118:Calcium
keywords: AKHR; CREB; Calcineurin; Calcium; GPCR; Insect; PKC