Unique features of HIV-1 Rev protein phosphorylation by protein kinase CK2 ('casein kinase-2').
The HIV-1 Rev transactivator is phosphorylated in vitro by protein kinase CK2 at two residues, Ser-5 and Ser-8; these sites are also phosphorylated in vivo. Here we show that the mechanism by which CK2 phosphorylates Rev is unique in several respects, notably: (i) it is fully dependent on the regulatory, beta-subunit of CK2; (ii) it relies on the integrity of an acidic stretch of CK2 beta which down-regulates the phosphorylation of other substrates; (iii) it is inhibited in a dose-dependent manner by polyamines and other polycationic effectors that normally stimulate CK2 activity. In contrast, a peptide corresponding to the amino-terminal 26 amino acids of Rev, including the phosphoacceptor site, is readily phosphorylated by the catalytic subunit of CK2 even in the absence of the beta-subunit. These data, in conjunction with the observation that two functionally inactive derivatives of Rev with mutations in its helix-loop-helix motif are refractory to phosphorylation, indicate the phosphorylation of Rev by CK2 relies on conformational features of distinct regions that are also required for the transactivator's biological activity.
Marin
O
O
Dipartmento di Chimica Biologica and Centro del CNR per lo Studio delle Biomembrane, Università delgi Studi di Padova, Padua, Italy.
Sarno
S
S
Boschetti
M
M
Pagano
M A
MA
Meggio
F
F
Ciminale
V
V
D'Agostino
D M
DM
Pinna
L A
LA
D000595:Amino Acid Sequence; D002147:Calmodulin / Q000737:chemistry / Q000378:metabolism; D047390:Casein Kinase II; D020134:Catalytic Domain; D004305:Dose-Response Relationship, Drug; D015694:Gene Products, rev / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1; D018257:Helix-Loop-Helix Motifs; D006493:Heparin / Q000494:pharmacology; D020035:Holoenzymes / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D010768:Phosphoserine / Q000378:metabolism; D011487:Protein Conformation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013096:Spermine / Q000494:pharmacology; D054321:rev Gene Products, Human Immunodeficiency Virus
D002147:Calmodulin; D015694:Gene Products, rev; D020035:Holoenzymes; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D054321:rev Gene Products, Human Immunodeficiency Virus; D010768:Phosphoserine; D013096:Spermine; D006493:Heparin; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases