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A novel nucleolar protein, NIFK, interacts with the forkhead associated domain of Ki-67 antigen in mitosis.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2001 Jul 06; Vol. 276 (27), pp. 25386-91. Date of Electronic Publication: 2001 May 07. - Publication Year :
- 2001
-
Abstract
- In a previous study, we demonstrated that the forkhead associated (FHA) domain of pKi-67 interacts with the novel kinesin-like protein, Hklp2 (Sueishi, M., Takagi, M., and Yoneda, Y. (2000) J. Biol. Chem. 275, 28888-28892). In this study, we report on the identification of a putative RNA-binding protein of 293 residues as another binding partner of the FHA domain of pKi-67 (referred to as NIFK for nucleolar protein interacting with the FHA domain of pKi-67). Human NIFK (hNIFK) interacted with the FHA domain of pKi-67 (Ki-FHA) efficiently in vitro when hNIFK was derived from mitotically arrested cells. In addition, a moiety of hNIFK was co-localized with pKi-67 at the peripheral region of mitotic chromosomes. The hNIFK domain that interacts with Ki-FHA was mapped in the yeast two-hybrid system to a portion encompassed by residues 226-269. In a binding assay utilizing Xenopus egg extracts, it was found that the mitosis-specific environment and two threonine residues within this portion of hNIFK (Thr-234 and Thr-238) were crucial for the efficient interaction of hNIFK and Ki-FHA, suggesting that hNIFK interacts with Ki-FHA in a mitosis-specific and phosphorylation-dependent manner. These findings provide a new clue to our understanding of the cellular function of pKi-67.
- Subjects :
- Amino Acid Sequence
Animals
Binding Sites
Carrier Proteins chemistry
Carrier Proteins genetics
Cell Cycle
Cloning, Molecular
HeLa Cells
Humans
Ki-67 Antigen chemistry
Mice
Microfilament Proteins
Molecular Sequence Data
Nuclear Proteins chemistry
Nuclear Proteins genetics
Peptide Mapping
Phosphorylation
Protein Binding
RNA-Binding Proteins
Threonine metabolism
Carrier Proteins metabolism
Drosophila Proteins
Insect Proteins chemistry
Intracellular Signaling Peptides and Proteins
Ki-67 Antigen metabolism
Mitosis
Nuclear Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 276
- Issue :
- 27
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 11342549
- Full Text :
- https://doi.org/10.1074/jbc.M102227200