title: Inhibition of CREB phosphorylation by conjugates of adenosine analogues and arginine-rich peptides, inhibitors of PKA catalytic subunit.
abstract: Bisubstrate inhibitors of protein kinases associate simultaneously with two substrate-binding sites of the kinase and thus potentially possess better inhibitory potency and selectivity than inhibitors binding to only the conserved ATP-site of the kinase. We have previously used conjugates of adenosine analogues and arginine-rich peptides (ARCs) to develop proteolytically stable cell plasma membrane-permeable bisubstrate inhibitors whose biochemical affinities towards several basophilic protein kinases of the AGC group are in the picomolar range. The potency of bisubstrate inhibitors to affect the phosphorylation of proteins in living cells has been described in a limited number of publications. In this study, the effect of ARCs on the protein kinase A (PKA)-catalysed cAMP response element-binding protein (CREB) phosphorylation pathway was studied in living mammalian cells. Our results demonstrate that at low micromolar extracellular concentration N-myristoylated ARCs are capable of reducing the activity of transcription factor CREB through inhibition of PKA.
authors.affiliation: Institute of Chemistry, University of Tartu, 14 A Ravila Street, 50411, Tartu (Estonia).
authors.forename: Marie
authors.initials: M
authors.lastname: Kriisa
authors.forename: Hedi
authors.initials: H
authors.lastname: Sinijärv
authors.forename: Angela
authors.initials: A
authors.lastname: Vaasa
authors.forename: Erki
authors.initials: E
authors.lastname: Enkvist
authors.forename: Sergiy
authors.initials: S
authors.lastname: Kostenko
authors.forename: Ugo
authors.initials: U
authors.lastname: Moens
authors.forename: Asko
authors.initials: A
authors.lastname: Uri
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000737:chemistry; D000818:Animals; D001120:Arginine; D016466:CHO Cells; D020134:Catalytic Domain; D003412:Cricetulus; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D057809:HEK293 Cells / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D020128:Inhibitory Concentration 50; D008156:Luciferases / Q000235:genetics; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; D010455:Peptides; D047428:Protein Kinase Inhibitors; D001120:Arginine; D008156:Luciferases; D017868:Cyclic AMP-Dependent Protein Kinases; D000241:Adenosine
keywords: CREB; inhibitors; nucleoside-peptide conjugates; phosphorylation; protein kinase A