Interaction of two multifunctional proteins. Heterogeneous nuclear ribonucleoprotein K and Y-box-binding protein.
The heterogeneous nuclear ribonucleoprotein (hnRNP) K, a component of the hnRNP particles, appears to be involved in several steps of regulation of gene expression. To gain insight into mechanisms of K protein action, we performed two-hybrid screens using full-length hnRNP K as a bait. Several novel protein partners were identified, including Y-box-binding protein (YB-1), splicing factors 9G8 and SRp20, DNA-methyltransferase, hnRNP L, and hnRNP U. In vitro binding studies and co-immunoprecipitation from cellular extracts provided evidence for direct interaction between hnRNP K and YB-1. Two distinct domains in YB-1 were responsible for binding to K protein. Each protein was able to transactivate transcription from a polypyrimidine-rich promoter; however, this effect was reduced when K and YB-1 proteins were coexpressed suggesting a functional interaction between these two proteins.
Shnyreva
M
M
Department of Medicine, University of Washington, Seattle, Washington 98195, USA.
Schullery
D S
DS
Suzuki
H
H
Higaki
Y
Y
Bomsztyk
K
K
D000818:Animals; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian; D015723:Gene Library; D006367:HeLa Cells; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D034664:Heterogeneous-Nuclear Ribonucleoprotein L; D034722:Heterogeneous-Nuclear Ribonucleoprotein U; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D034664:Heterogeneous-Nuclear Ribonucleoprotein L; D034722:Heterogeneous-Nuclear Ribonucleoprotein U; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human