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Necdin interacts with the ribonucleoprotein hnRNP U in the nuclear matrix
Author(s) -
Taniura Hideo,
Yoshikawa Kazuaki
Publication year - 2002
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.10047
Subject(s) - heterogeneous nuclear ribonucleoprotein , nuclear matrix , ribonucleoprotein , complementary dna , microbiology and biotechnology , heterogeneous ribonucleoprotein particle , nucleolus , nuclear protein , biology , transfection , cell nucleus , scaffold/matrix attachment region , chemistry , dna , rna , cell culture , gene , biochemistry , genetics , nucleus , transcription factor , histone , chromatin remodeling , chromatin
Abstract Necdin is expressed predominantly in terminally differentiated neurons, and its ectopic expression suppresses cell proliferation. We screened a cDNA library from neurally differentiated embryonal carcinoma P19 cells for necdin‐binding proteins by the yeast two‐hybrid assay. One of the positive clones contained cDNA encoding a carboxyl‐terminal portion of heterogeneous nuclear ribonucleoprotein U (hnRNP U), a nuclear matrix‐associated protein that interacts with chromosomal DNA. We isolated cDNA encoding full‐length mouse hnRNP U to analyze its physical and functional interactions with necdin. The necdin‐binding site of hnRNP U was located near a carboxyl‐terminal region that mediated the association between hnRNP U and the nuclear matrix. In postmitotic neurons, endogenously expressed necdin and hnRNP U were detected in the nuclear matrix and formed a stable complex. Ectopically expressed necdin was concentrated in the nucleoli, but coexpressed hnRNP U recruited necdin to the nucleoplasmic compartment of the nuclear matrix. Furthermore, under the same conditions necdin and hnRNP U cooperatively suppressed the colony formation of transfected SAOS‐2 cells. These results suggest that necdin suppresses cell proliferation through its interaction with hnRNP U in the specific subnuclear structure. J. Cell. Biochem. 84: 545–555, 2002. © 2001 Wiley‐Liss, Inc.