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WormBook: The Online Review of C. elegans Biology [Internet]. Pasadena (CA): WormBook; 2005-2018.
| C. elegans protein | C. elegans gene | Required for embryonic viability? | Vertebrate orthologue | Summary of localization and functional analysis | Selected references |
|---|---|---|---|---|---|
| CeCENP-A, HCP-3 | hcp-3; (F58A4 | YES | CENP-A | Histone H3-variant; thought to localize to chromatin throughout the cell cycle; found in nuclear foci during interphase and concentrated on the chromatin in a stripe that runs along the poleward face of each sister chromatid during mitosis; CeCENP-A is required for the localization of all other kinetochore components that have been tested; depletion results in failure to align and segregate mitotic chromosomes and premature spindle elongation due to the inability of the kinetochores to attach to spindle microtubules; a highly homologous gene (F54C8 | Buchwitz, 1999; Oegema, 2001 |
| CeCENP-C, HCP-4 | hcp-4; (T03F1 | YES | CENP-C | Kinetochore localization (prophase to telophase) requires CeCENP-A; CeCENP-C is required for the localization of all kinetochore proteins except CeCENP-A; associates with the KNL-1/3 complex and may act as an adaptor to connect centromeric chromatin to the outer kinetochore; plays a role in the resolution of CeCENP-A chromatin into two paired "lines" on the replicated chromosome; depletion results in failure to align and segregate mitotic chromosomes and premature spindle elongation. | Moore, 2001; Oegema, 2001; Desai, 2003; Cheeseman, 2004 |
| KNL-3 | knl-3 (T10B5 | YES | ? | Kinetochore localization (prophase to telophase) requires CeCENP-A and CeCENP-C; KNL-3 levels at the kinetochore are reduced in embryos depleted of MIS-12, KBP-1, KBP-2 and KNL-1; depletion results in failure to align and segregate mitotic chromosomes and premature spindle elongation; component of the 10-protein KNL-1/3 complex required to assemble an outer kinetochore that can make microtubule attachments. | Cheeseman, 2004 |
| KNL-1 | knl-1 (C02F5 | YES | AF15q14 | Kinetochore localization (prophase to telophase) requires CeCENP-A, CeCENP-C and KNL-3; KNL-1 levels at the kinetochores are reduced in embryos depleted of NDC-80 and HIM-10; depletion results in failure to align and segregate mitotic chromosomes and premature spindle elongation. Component of the 10-protein KNL-1/3 complex required to assemble an outer kinetochore that can make microtubule attachments. | Desai, 2003 Cheeseman, 2004 |
| MIS-12 | mis-12 (Y47G6A | YES | Mis12 | Kinetochore localization (prophase to telophase) requires KNL-3 but not KNL-1; relatively weak chromosome missegregation phenotype seen in depleted embryos consistent with a delay in the formation of chromosome- spindle attachments; identified by sequence homology to human and fission yeast Mis12 and as a component of the KNL-1/3 complex. | Cheeseman, 2004 |
| KBP-1 | kbp-1 (R13F6 | YES | ? | Localizes to kinetochores from prophase to telophase; relatively weak chromosome missegregation phenotype seen in depleted embryos consistent with a delay in the formation of chromosome- spindle attachments; identified as a component of the KNL-1/3 complex. | Cheeseman, 2004 |
| KBP-2 | kbp-2 (F26F4 | YES | ? | Localizes to kinetochores from prophase to telophase; relatively weak chromosome missegregation phenotype seen in depleted embryos consistent with a delay in the formation of chromosome- spindle attachments; identified as a component of the KNL-1/3 complex. | Cheeseman, 2004 |
| NDC-80 | ndc-80 (W01B6.9.1) | YES | Ndc80/HEC | Localizes to kinetochores from prophase to telophase; kinetochore localization requires KNL-1 and HIM-10 in addition to chromatin- proximal components; depletion results in chromosome missegregation and premature spindle elongation; phenotype is less severe than a kinetochore-null but more severe than that of MIS-12, suggests defect in the ability to form microtubule attachments that can withstand tension; member of the NDC-80 subcomplex, which is part of the larger KNL-1/3 complex. | Desai, 2003 Cheeseman, 2004 |
| HIM-10 Nuf2HIM-10 | him-10 (R12B2 | YES | Nuf2 | Localizes to kinetochores from prophase to telophase; kinetochore localization requires KNL-1 and NDC-80, in addition to chromatin- proximal components. Depletion disrupts kinetochore ultrastructure, resulting in chromosome missegregation and premature spindle elongation; phenotype is less severe than a kinetochore-null but more severe than that of MIS-12, suggests defect in the ability to form microtubule attachments that can withstand tension; member of the NDC-80 subcomplex, which is part of the larger KNL-1/3 complex. | Howe, 2001 Desai, 2003 Cheeseman, 2004 |
| KBP-3 | kbp-3 (F26H11 | YES | Spc25 | Localizes to kinetochores from prophase to telophase; depletion results in chromosome missegregation and premature spindle elongation; phenotype is less severe than a kinetochore-null but more severe than that of MIS-12, suggests defect in the ability to form microtubule attachments that can withstand tension; member of the NDC-80 subcomplex, which is part of the larger KNL-1/3 complex. | Cheeseman, 2004 |
| KBP-4 | kbp-4 (Y92C3B | YES | ? | Localizes to kinetochores from prophase to telophase. Depletion results in chromosome missegregation and premature spindle elongation; phenotype is less severe than a kinetochore-null but more severe than that of MIS-12, suggests defect in the ability to form microtubule attachments that can withstand tension; identified as a KNL-1/3-associated protein. | Cheeseman, 2004 |
| KBP-5 | kbp-5 (C34B2 | NO | ? | Localizes to kinetochores from prophase to telophase. Identified as a KNL-1/3-associated protein. | Cheeseman, 2004 |
| HCP-1 HCP-2 | hcp-1 (ZK1055 | YES* *When co-depleted | CENP-F? | Functionally redundant proteins that localize to the region of the mitotic spindle and to kinetochores between late prometaphase and early anaphase; kinetochore localization requires CeCENP-A/C, KNL-1, and BUB-1, but not the NDC-80 subcomplex; depletion perturbs chromosome alignment and segregation. HCP-1 and 2 physically associate with CLASPCLS-2. | Moore, 1999; Desai, 2003; Stear, 2004; Encalada, 2004; Cheeseman, 2005 |
| CLASPcls-2 (CLS-2) | cls-2 (R107 | YES | CLASP | Microtubule- associated protein that localizes to spindle poles, the region of the miotic spindle and kinetochores; prominent kinetochore localization is seen at metaphase. Kinetochore localization requires KNL-1 and HCP-1/2, but not the NDC-80 subcomplex. Depletion perturbs chromosome alignment and segregation. CLASPCLS-2 associates with HCP-1/2. | Desai, 2003; Cheeseman, 2005 |
| CeMCAK (KLP-7) | klp-7 (K11D9.1) | YES | MCAK | Kinesin-13 microtubule depolymerase that localizes to kinetochores between early prometaphase and telophase, and to spindle poles throughout mitosis; kinetochore localization requires CeCENP-A and CeCENP-C, but not KNL-1 or KNL-3; depletion results in snapping of the anaphase spindle, suggesting excessive astral pulling forces or a defect in spindle midzone formation/stability. | Oegema, 2001; Grill, 2001; Desai, 2003; Powers, 2004 |
| LIS-1 | lis-1 (T03F6 | YES | LIS1 | Microtubule associated protein that localizes to the cell cortex, nuclear periphery, kinetochores, and microtubule asters; kinetochore localization requires CeCENP-C, but not dynein; depletion results in multiple defects in spindle positioning, pronuclear migration, and centrosome separation, leading to gross missegregation of chromosomes. | Cockell, 2004 |
| CZW-1 | czw-1 (F20D12 | YES | Zw10 | Predicted kinetochore protein based on sequence homology; partial depletion results in chromosome missegregation; penetrant depletion results in sterility | Starr, 1998 |
| ROD-1 | rod-1 (F55G1 | YES | Rod | Predicted kinetochore protein based on sequence homology; depletion results in chromosome missegregation. | Scaerou, 2001 |
| BUB-1 | bub-1 (R06C7 | YES | Bub1 | Mitotic checkpoint pathway serine/threonine protein kinase; kinetochore localization (prophase to metaphase) requires CeCENP-A, CeCENP-C, and KNL-1; depletion results in misalignment and missegregation of chromosomes. | Oegema, 2001; Desai, 2003; Encalada, 2004 |
| BUB-3 | Y54G9A | NO | Bub3 | Predicted mitotic checkpoint pathway protein based on sequence homology. | |
| MDF-1 | mdf-1 (C50F4 | NO | Mad1 | Mitotic checkpoint pathway protein based on sequence homology; mutant worms fail to thrive due to accumulated chromosomal abnormalities; required to delay the embryonic cell cycle in response to spindle defects. | Kitagawa, 1999; Encalada, 2004 |
| MDF-2 | mdf-2 (Y69A2AR. 30) | NO | Mad2 | Mitotic checkpoint pathway protein with similar functions as MDF-1; depletion of MDF-2 also overrides the mitotic arrest induced by anoxia, suggesting that survival under very low oxygen levels is promoted by activation of the mitotic checkpoint. | Kitagawa, 1999; Nystul, 2003; Encalada, 2004 |
| SAN-1 | san-1 (ZC328 | NO | BubR1 | Mitotic checkpoint pathway protein that localizes to kinetochores after nuclear envelope breakdown. SAN-1 is the homologue of budding yeast MAD3 protein (their vertebrate orthologue, BubR1, has a serine/threonine kinase domain fused to the Mad3 homology region). SAN-1 was identified in a genetic screen for anoxia-sensitive mutants, highlighting a link between survival under very low oxygen levels and mitotic arrest mediated by the mitotic checkpoint pathway. | Nystul, 2004 |
From: Cell division
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