A new G-stretch-DNA-binding protein, Unichrom, displays cell-cycle-dependent expression in sea urchin embryos.
We report the identification and characterization of Unichrom, a gene encoding a new G-stretch-DNA-binding protein in the sea urchin embryo. The derived amino acid sequence of Unichrom contains plant homeodomain (PHD) finger and high mobility group (HMG) motifs as well as motifs required for cell-cycle-dependent degradation. The expression of a Unichrom-green fluorescent protein (GFP) fusion protein in sea urchin embryonic cells indicates that Unichrom protein accumulates in nuclei during interphase and disperses into the cytoplasm at mitosis. Overexpression of dominant negative Unichrom, which contains the DNA binding domain lacking the motif for cell-cycle-dependent degradation, causes impairment of chromosome segregation. These results suggest that Unichrom binds to genome DNA at G-stretch and that degradation of Unichrom is required for segregation of chromosomes.
Moritani
Kosho
K
Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
Tagashira
Hideki
H
Shimotori
Taishin
T
Sakamoto
Naoaki
N
Tanaka
Shin
S
Takata
Kazuko
K
Mitsunaga-Nakatsubo
Keiko
K
Bojiiwa
Yuto
Y
Yamamoto
Takashi
T
Shimada
Hiraku
H
Akasaka
Koji
K
D000595:Amino Acid Sequence; D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D006609:High Mobility Group Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D012617:Sea Urchins / Q000196:embryology*
D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins