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HCP-4, a CENP-C-like protein in Caenorhabditis elegans, is required for resolution of sister centromeres.

Moore LL, Roth MB - J. Cell Biol. (2001)

Bottom Line: HCP-4 is found in the cytoplasm during interphase, but is nuclear localized in mitosis, where it localizes specifically to the centromere.The localization of HCP-4 to the centromere is dependent on the centromeric histone HCP-3; in addition, HCP-3 and HCP-4 are both required for localization of a CENP-F-like protein, HCP-1, indicating an ordered assembly pathway.These chromosomes also failed to form a functional kinetochore.

View Article: PubMed Central - PubMed

Affiliation: Division of Basic Sciences, Molecular and Cellular Biology Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.

ABSTRACT
The centromere plays a critical role in the segregation of chromosomes during mitosis. In mammals, sister centromeres are resolved from one another in the G2 phase of the cell cycle. During prophase, chromosomes condense with sister centromeres oriented in a back to back configuration enabling only one chromatid to be captured by each half spindle. To study this process, we identified a centromere protein (CENP)-C-like protein, holocentric protein (HCP)-4, in Caenorhabditis elegans based on sequence identity, loss of function phenotype, and centromeric localization. HCP-4 is found in the cytoplasm during interphase, but is nuclear localized in mitosis, where it localizes specifically to the centromere. The localization of HCP-4 to the centromere is dependent on the centromeric histone HCP-3; in addition, HCP-3 and HCP-4 are both required for localization of a CENP-F-like protein, HCP-1, indicating an ordered assembly pathway. Loss of HCP-4 expression by RNA-mediated interference resulted in a failure to generate resolution of sister centromeres on chromosomes, suggesting that HCP-4 is required for sister centromere resolution. These chromosomes also failed to form a functional kinetochore. Thus, the CENP-C-like protein HCP-4 is essential for both resolution sister centromeres and attachment to the mitotic spindle.

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Sequence and alignment of HCP-4 with CENP-C proteins. BLOCKMAKER and the Motif Alignment and Search Tool programs were used with human CENP-C (EMBL/GenBank/DDBJ accession no. M95724), mouse CENP-C (EMBL/GenBank/DDBJ accession no. U03113), chicken CENP-C (EMBL/GenBank/DDBJ accession no. AB004649), and MIF2 (EMBL/GenBank/DDBJ accession no. Z28089) to identify a region of similarity in HCP-4 (Bailey and Gribskov 1998; Henikoff and Henikoff 1991). Alignment was performed using the ClustalW multiple alignment program (Thompson et al. 1994) and displayed using Boxshade (http://www.ch.embnet.org/software/BOX_form.html). Identities are shaded black.
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Figure 1: Sequence and alignment of HCP-4 with CENP-C proteins. BLOCKMAKER and the Motif Alignment and Search Tool programs were used with human CENP-C (EMBL/GenBank/DDBJ accession no. M95724), mouse CENP-C (EMBL/GenBank/DDBJ accession no. U03113), chicken CENP-C (EMBL/GenBank/DDBJ accession no. AB004649), and MIF2 (EMBL/GenBank/DDBJ accession no. Z28089) to identify a region of similarity in HCP-4 (Bailey and Gribskov 1998; Henikoff and Henikoff 1991). Alignment was performed using the ClustalW multiple alignment program (Thompson et al. 1994) and displayed using Boxshade (http://www.ch.embnet.org/software/BOX_form.html). Identities are shaded black.

Mentions: Because CENP-C–like proteins are associated with centromeric heterochromatin and are present when sister centromeres are resolved from one another, we wanted to study the function of CENP-C in C. elegans. To do this, we searched for a CENP-C–like protein in C. elegans. We identified the predicted ORF T03F1.9 as containing a short sequence of similarity to CENP-C–like proteins (Fig. 1). We named T03F1.9, HCP-4.


HCP-4, a CENP-C-like protein in Caenorhabditis elegans, is required for resolution of sister centromeres.

Moore LL, Roth MB - J. Cell Biol. (2001)

Sequence and alignment of HCP-4 with CENP-C proteins. BLOCKMAKER and the Motif Alignment and Search Tool programs were used with human CENP-C (EMBL/GenBank/DDBJ accession no. M95724), mouse CENP-C (EMBL/GenBank/DDBJ accession no. U03113), chicken CENP-C (EMBL/GenBank/DDBJ accession no. AB004649), and MIF2 (EMBL/GenBank/DDBJ accession no. Z28089) to identify a region of similarity in HCP-4 (Bailey and Gribskov 1998; Henikoff and Henikoff 1991). Alignment was performed using the ClustalW multiple alignment program (Thompson et al. 1994) and displayed using Boxshade (http://www.ch.embnet.org/software/BOX_form.html). Identities are shaded black.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2192019&req=5

Figure 1: Sequence and alignment of HCP-4 with CENP-C proteins. BLOCKMAKER and the Motif Alignment and Search Tool programs were used with human CENP-C (EMBL/GenBank/DDBJ accession no. M95724), mouse CENP-C (EMBL/GenBank/DDBJ accession no. U03113), chicken CENP-C (EMBL/GenBank/DDBJ accession no. AB004649), and MIF2 (EMBL/GenBank/DDBJ accession no. Z28089) to identify a region of similarity in HCP-4 (Bailey and Gribskov 1998; Henikoff and Henikoff 1991). Alignment was performed using the ClustalW multiple alignment program (Thompson et al. 1994) and displayed using Boxshade (http://www.ch.embnet.org/software/BOX_form.html). Identities are shaded black.
Mentions: Because CENP-C–like proteins are associated with centromeric heterochromatin and are present when sister centromeres are resolved from one another, we wanted to study the function of CENP-C in C. elegans. To do this, we searched for a CENP-C–like protein in C. elegans. We identified the predicted ORF T03F1.9 as containing a short sequence of similarity to CENP-C–like proteins (Fig. 1). We named T03F1.9, HCP-4.

Bottom Line: HCP-4 is found in the cytoplasm during interphase, but is nuclear localized in mitosis, where it localizes specifically to the centromere.The localization of HCP-4 to the centromere is dependent on the centromeric histone HCP-3; in addition, HCP-3 and HCP-4 are both required for localization of a CENP-F-like protein, HCP-1, indicating an ordered assembly pathway.These chromosomes also failed to form a functional kinetochore.

View Article: PubMed Central - PubMed

Affiliation: Division of Basic Sciences, Molecular and Cellular Biology Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.

ABSTRACT
The centromere plays a critical role in the segregation of chromosomes during mitosis. In mammals, sister centromeres are resolved from one another in the G2 phase of the cell cycle. During prophase, chromosomes condense with sister centromeres oriented in a back to back configuration enabling only one chromatid to be captured by each half spindle. To study this process, we identified a centromere protein (CENP)-C-like protein, holocentric protein (HCP)-4, in Caenorhabditis elegans based on sequence identity, loss of function phenotype, and centromeric localization. HCP-4 is found in the cytoplasm during interphase, but is nuclear localized in mitosis, where it localizes specifically to the centromere. The localization of HCP-4 to the centromere is dependent on the centromeric histone HCP-3; in addition, HCP-3 and HCP-4 are both required for localization of a CENP-F-like protein, HCP-1, indicating an ordered assembly pathway. Loss of HCP-4 expression by RNA-mediated interference resulted in a failure to generate resolution of sister centromeres on chromosomes, suggesting that HCP-4 is required for sister centromere resolution. These chromosomes also failed to form a functional kinetochore. Thus, the CENP-C-like protein HCP-4 is essential for both resolution sister centromeres and attachment to the mitotic spindle.

Show MeSH
Related in: MedlinePlus