PMID- 10094406
OWN - NLM
STAT- MEDLINE
DCOM- 19990429
LR  - 20211203
IS  - 0300-8177 (Print)
IS  - 0300-8177 (Linking)
VI  - 191
IP  - 1-2
DP  - 1999 Jan
TI  - A role for casein kinase II phosphorylation in the regulation of IRF-1
      transcriptional activity.
PG  - 169-80
AB  - The Interferon Regulatory Factors (IRFS) play an important role in the
      transcriptional control of growth regulatory and immunoregulatory genes. The
      inducibility and availability of IRF-1 and IRF-2 are influenced by external
      stimuli, such as virus infection or interferon treatment. In the present study,
      we sought to examine the potential modulatory role of phosphorylation on IRF-1
      transcriptional activity. During the purification of IRF recombinant proteins, a 
      kinase activity copurified with IRF-1 (and IRF-2) from baculovirus infected Sf9
      insect cell extracts, but not from E. coli extracts. The kinase activity was also
      identified in Jurkat T cells, specifically interacted with IRF proteins in GST
      affinity chromatography, and phosphorylated IRF-1 with high specificity in vitro.
      Using an in gel kinase assay with recombinant IRF-1 as substrate, two molecular
      weight forms of the kinase (43 and 38 kDa) were identified. Biochemical criteria 
      identified the kinase activity as the alpha catalytic subunit of casein kinase II
      (CKII). Furthermore, far western analysis of protein-protein interactions
      demonstrated that casein kinase II directly interacted with IRF-1 protein.
      Deletion mutation analysis of IRF-1 revealed that IRF-1 was phosphorylated at two
      clustered sites, one located between amino acids 138-150, the other in the
      C-terminal acidic activation domain between amino acids 219-231. Cotransfection
      studies comparing wild type and point mutated forms of IRF-1 demonstrated that
      mutations of the four phosphoaceptor residues in the C-terminal transactivation
      domain, significantly decreased transactivation by IRF-1, indicating that casein 
      kinase II may be involved in the regulation of IRF-1 function. Strikingly, the
      casein kinase II clusters in IRF-1 resemble the sites identified in the
      C-terminal PEST domain of IkappaBalpha. The present experiments, together with
      previously published studies with IkappaBalpha, c-Jun and other proteins,
      indicate a broad role for casein kinase II phosphorylation in the regulation of
      transcription factor activity.
FAU - Lin, R
AU  - Lin R
AD  - Lady Davis Institute for Medical Research, and Department of Medicine, McGill
      University, Montreal, Quebec, Canada.
FAU - Hiscott, J
AU  - Hiscott J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Mol Cell Biochem
JT  - Molecular and cellular biochemistry
JID - 0364456
RN  - 0 (DNA-Binding Proteins)
RN  - 0 (IRF1 protein, human)
RN  - 0 (Interferon Regulatory Factor-1)
RN  - 0 (Interferon Type I)
RN  - 0 (Phosphoproteins)
RN  - 0 (Transcription Factors)
RN  - EC 2.7.11.1 (Casein Kinase II)
RN  - EC 2.7.11.1 (Protein Serine-Threonine Kinases)
SB  - IM
MH  - Blotting, Western
MH  - Casein Kinase II
MH  - Cell Line
MH  - DNA-Binding Proteins/*metabolism
MH  - Humans
MH  - Interferon Regulatory Factor-1
MH  - Interferon Type I/*metabolism
MH  - Phosphoproteins/*metabolism
MH  - Phosphorylation
MH  - Protein Binding
MH  - Protein Processing, Post-Translational
MH  - Protein Serine-Threonine Kinases/*metabolism
MH  - Transcription Factors/*metabolism
MH  - *Transcription, Genetic
EDAT- 1999/03/27 00:00
MHDA- 1999/03/27 00:01
CRDT- 1999/03/27 00:00
PHST- 1999/03/27 00:00 [pubmed]
PHST- 1999/03/27 00:01 [medline]
PHST- 1999/03/27 00:00 [entrez]
PST - ppublish
SO  - Mol Cell Biochem. 1999 Jan;191(1-2):169-80.