title: Targeted disruption of one allele of the Y-box protein gene, Chk-YB-1b, in DT40 cells results in major defects in cell cycle.
abstract: Y-box or inverted CCAAT box-binding proteins are multifunctional regulators of transcription and translation of several genes. Although YB-1 has been shown to play a key role in cell cycle, to date, there is no direct evidence. We disrupted one allele of Chk-YB-1b in a chicken pre-B lymphocyte cell line, DT40. Compared to wild-type DT40 cells, these heterozygous DT40YB1b(+/-) cells with one copy of the wild-type Chk-YB-1b allele showed multiple abnormalities, which include slower rate of growth, abnormal cell morphology, increased cell size, and increased genomic DNA content. These phenotypic defects resemble those cells that have a block in G2 and/or mitosis (G2/M). In addition, we have observed that a fraction of these heterozygous DT40YB1b(+/-) cells undergo apoptosis. In conclusion, we have discovered major defects in the G2/M phase of cell cycle in YB-1 knocked-out heterozygous mutant cells, providing for the first time direct evidence establishing a crucial role for YB-1 in cell proliferation.
authors.affiliation: Department of Molecular Microbiology and Immunology, University of Missouri, School of Medicine, Columbia, MO, USA.
authors.forename: Shivalingappa K
authors.initials: SK
authors.lastname: Swamynathan
authors.forename: Balwantkumar R
authors.initials: BR
authors.lastname: Varma
authors.forename: Karl T
authors.initials: KT
authors.lastname: Weber
authors.forename: Ramareddy V
authors.initials: RV
authors.lastname: Guntaka
mesh_terms: D000483:Alleles; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology*; D002460:Cell Line; D002469:Cell Separation; D002645:Chickens; D004268:DNA-Binding Proteins; D005434:Flow Cytometry; D018390:Gene Targeting; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D051840:Y-Box-Binding Protein 1
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human