Cloning and characterization of DIP1, a novel protein that is related to the Id family of proteins.
Using human cyclin D1 as the "bait" in a yeast two-hybrid system, together with a HL60 cDNA library, we identified a novel human nuclear protein designated DIP1. This protein is expressed in a variety of cell types, and in fibroblasts its level remains constant throughout the cell cycle. However, the level of this protein increases severalfold during the differentiation of HL60 cells. The DIP1 protein can be phosphorylated in vitro by a cellular kinase and this activity reaches its maximum in extracts obtained from cells in the G1 phase of the cell cycle. DIP1 contains a helix-loop-helix motif but lacks an adjacent basic DNA-binding domain, thus resembling the Id family of proteins. The dip1 gene is located on human chromosome 16p11.2-12, a locus that is amplified in several types of human cancer. These results suggest that DIP1 may be involved in the control of gene expression and differentiation, but its precise function remains to be determined.
Yao
Y
Y
Herbert Irving Comprehensive Cancer Center, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA.
Doki
Y
Y
Jiang
W
W
Imoto
M
M
Venkatraj
V S
VS
Warburton
D
D
Santella
R M
RM
Lu
B
B
Yan
L
L
Sun
X H
XH
Su
T
T
Luo
J
J
Weinstein
I B
IB
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D019938:Cyclin D1 / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D029721:Drosophila Proteins; D018922:HL-60 Cells; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics*; D012097:Repressor Proteins; D016415:Sequence Alignment; D017421:Sequence Analysis; D014157:Transcription Factors / Q000235:genetics*
C485815:CCNDBP1 protein, human; C410062:DISCO Interacting Protein 1, Drosophila; D018076:DNA, Complementary; D029721:Drosophila Proteins; C497453:ID1 protein, human; D051798:Inhibitor of Differentiation Protein 1; D009687:Nuclear Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D019938:Cyclin D1