Publications (2)7.16 Total impact
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Article: Identification and characterization of INMAP, a novel interphase nucleus and mitotic apparatus protein that is involved in spindle formation and cell cycle progression.
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ABSTRACT: A novel protein that associates with interphase nucleus and mitotic apparatus (INMAP) was identified by screening HeLa cDNA expression library with an autoimmune serum followed by tandem mass spectrometry. Its complete cDNA sequence of 1.818 kb encodes 343 amino acids with predicted molecular mass of 38.2 kDa and numerous phosphorylation sites. The sequence is identical with nucleotides 1-1800 bp of an unnamed gene (GenBank accession no. 7022388) and highly homologous with the 3'-terminal sequence of POLR3B. A monoclonal antibody against INMAP reacted with similar proteins in S. cerevisiae, Mel and HeLa cells, suggesting that it is a conserved protein. Confocal microscopy using either GFP-INMAP fusion protein or labeling with the monoclonal antibody revealed that the protein localizes as distinct dots in the interphase nucleus, but during mitosis associates closely with the spindle. Double immunolabeling using specific antibodies showed that the INMAP co-localizes with alpha-tubulin, gamma-tubulin, and NuMA. INMAP also co-immunoprecipitated with these proteins in their native state. Stable overexpression of INMAP in HeLa cell lines leads to defects in the spindle, mitotic arrest, formation of polycentrosomal and multinuclear cells, inhibition of growth, and apoptosis. We propose that INMAP is a novel protein that plays essential role in spindle formation and cell-cycle progression.Experimental Cell Research 05/2009; 315(7):1100-16. · 3.58 Impact Factor -
Article: Identification of a novel centrosomal protein CrpF46 involved in cell cycle progression and mitosis.
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ABSTRACT: A novel centrosome-related protein CrpF46 was detected using a serum F46 from a patient suffering from progressive systemic sclerosis. We identified the protein by immunoprecipitation and Western blotting followed by tandem mass spectrometry sequencing. The protein CrpF46 has an apparent molecular mass of ~60 kDa, is highly homologous to a 527 amino acid sequence of the C-terminal portion of the protein Golgin-245, and appears to be a splice variant of Golgin-245. Immunofluorescence microscopy of synchronized HeLa cells labeled with an anti-CrpF46 monoclonal antibody revealed that CrpF46 localized exclusively to the centrosome during interphase, although it dispersed throughout the cytoplasm at the onset of mitosis. Domain analysis using CrpF46 fragments in GFP-expression vectors transformed into HeLa cells revealed that centrosomal targeting is conferred by a C-terminal coiled-coil domain. Antisense CrpF46 knockdown inhibited cell growth and proliferation and the cell cycle typically stalled at S phase. The knockdown also resulted in the formation of poly-centrosomal and multinucleate cells, which finally became apoptotic. These results suggest that CrpF46 is a novel centrosome-related protein that associates with the centrosome in a cell cycle-dependent manner and is involved in the progression of the cell cycle and M phase mechanism.Experimental Cell Research 06/2008; 314(8):1693-707. · 3.58 Impact Factor
