HIV-1 Rev transactivator: a beta-subunit directed substrate and effector of protein kinase CK2.
The phosphorylation of HIV-1 Rev by protein kinase CK2 is strictly dependent on the regulatory beta subunit of the kinase and is deeply affected by conformational changes of the substrate outside the phosphorylation site. Here we show that Rev modulates a variety of CK2 properties, including autophosphorylation, catalytic activity toward calmodulin, and susceptibility to polycationic effectors, whose common denominator is the involvement of the beta subunit. Rev's two major CK2 sites are located at its N-terminus, immediately adjacent to a helix-loop-helix motif. By comparing the behaviour of full-size Rev with that of synthetic peptides reproducing, with suitable modifications, its N-terminal 26 amino acids including the phosphoacceptor site (Ser 5, Ser 8) and amphipathic helix-1, it appears that the functional interaction of the N-terminal portion of Rev with the N-terminal domain of the beta subunit must rely on both electrostatic and hydrophobic interactions. The former mainly involve Rev's arginine-rich domain (residues 35-50) in helix-2, while the latter are mostly mediated by residues 12-24 of helix-1. These data disclose the possibility that, besides displaying protective, regulatory and targeting properties with respect to the catalytic subunit, the CK2 beta subunit also plays a role as a docking site for a subset of CK2 substrates.
Meggio
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F
Dipartimento di Chimica Biologica, Centro di Studio delle Biomembrane del CNR, Padova, Italy. meggio@civ.bio.unipd.it
Marin
O
O
Boschetti
M
M
Sarno
S
S
Pinna
L A
LA
D020816:Amino Acid Motifs; D000818:Animals; D001120:Arginine / Q000737:chemistry; D001665:Binding Sites; D002147:Calmodulin / Q000378:metabolism; D047390:Casein Kinase II; D002384:Catalysis; D002852:Chromatography, Ion Exchange; D003902:Detergents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015694:Gene Products, rev / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D017830:Octoxynol / Q000494:pharmacology; D010766:Phosphorylation; D011107:Polylysine / Q000737:chemistry; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism
D002147:Calmodulin; D003902:Detergents; D015694:Gene Products, rev; D011994:Recombinant Proteins; D011107:Polylysine; D017830:Octoxynol; D001120:Arginine; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases