Publication Date:
1993-03-12
Description:
PU.1 recruits the binding of a second B cell-restricted nuclear factor, NF-EM5, to a DNA site in the immunoglobulin kappa 3' enhancer. DNA binding by NF-EM5 requires a protein-protein interaction with PU.1 and specific DNA contacts. Dephosphorylated PU.1 bound to DNA but did not interact with NF-EM5. Analysis of serine-to-alanine mutations in PU.1 indicated that serine 148 (Ser148) is required for protein-protein interaction. PU.1 produced in bacteria did not interact with NF-EM5. Phosphorylation of bacterially produced PU.1 by purified casein kinase II modified it to a form that interacted with NF-EM5 and that recruited NF-EM5 to bind to DNA. Phosphopeptide analysis of bacterially produced PU.1 suggested that Ser148 is phosphorylated by casein kinase II. This site is also phosphorylated in vivo. Expression of wild-type PU.1 increased expression of a reporter construct containing the PU.1 and NF-EM5 binding sites nearly sixfold, whereas the Ser148 mutant form only weakly activated transcription. These results demonstrate that phosphorylation of PU.1 at Ser148 is necessary for interaction with NF-EM5 and suggest that this phosphorylation can regulate transcriptional activity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pongubala, J M -- Van Beveren, C -- Nagulapalli, S -- Klemsz, M J -- McKercher, S R -- Maki, R A -- Atchison, M L -- AI 30656/AI/NIAID NIH HHS/ -- CA 42909/CA/NCI NIH HHS/ -- GM 42415/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1993 Mar 12;259(5101):1622-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Animal Biology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia 19104.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8456286" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
B-Lymphocytes/immunology
;
Base Sequence
;
Cell Line
;
Cell Nucleus/metabolism
;
DNA-Binding Proteins/genetics/isolation & purification/*metabolism
;
Enhancer Elements, Genetic
;
Immunoglobulin kappa-Chains/genetics
;
Molecular Sequence Data
;
Mutagenesis, Site-Directed
;
Oligonucleotide Probes
;
Phosphorylation
;
Plasmacytoma
;
Recombinant Proteins/isolation & purification/metabolism
;
Retroviridae Proteins, Oncogenic
;
Transcription Factors/*metabolism
;
*Transcription, Genetic
;
Transfection
;
Tumor Cells, Cultured
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
