Identification of novel mitosis regulators through data mining with human centromere/kinetochore proteins as group queries

Abstract

BackgroundProteins functioning in the same biological pathway tend to be transcriptionally co-regulated or form protein-protein interactions (PPI). Multiple spatially and temporally regulated events are coordinated during mitosis to achieve faithful chromosome segregation. The molecular players participating in mitosis regulation are still being unravelled experimentally or using in silico methods.ResultsAn extensive literature review has led to a compilation of 196 human centromere/kinetochore proteins, all with experimental evidence supporting the subcellular localization. Sixty-four were designated as “core” centromere/kinetochore components based on peak expression and/or well-characterized functions during mitosis. By interrogating and integrating online resources, we have mined for genes/proteins that display transcriptional co-expression or PPI with the core centromere/kinetochore components. Top-ranked hubs in either co-expression or PPI network are not only enriched with known mitosis regulators, but also contain candidates whose mitotic functions are not yet established. Experimental validation found that KIAA1377 is a novel centrosomal protein that also associates with microtubules and midbody; while TRIP13 is a novel kinetochore protein and directly interacts with mitotic checkpoint silencing protein p31comet.ConclusionsTranscriptional co-expression and PPI network analyses with known human centromere/kinetochore proteins as a query group help identify novel potential mitosis regulators.

Disassembly of mitotic checkpoint complexes by the joint action of the AAA-ATPase TRIP13 and p31 comet

“…[17][18][19]. It has been reported that the AAA-ATPase TRIP13 is a kinetochoreassociated protein that binds to p31 comet (16). Because the Cdc20-Mad2 substrate used in our assay contained p31 comet (necessary for the release of the subcomplex from MCC), TRIP13 seemed to be a likely candidate.…”

“…The Mad2-binding protein p31 comet has important roles in checkpoint inactivation (11,12,14,(20)(21)(22) and MCC disassembly (10,21), and has been reported to bind to TRIP13 (16). We therefore examined whether the actions of TRIP13 described above require the participation of p31 comet .…”

“…chromatin (26)(27)(28). A different function of TRIP13 has been suggested by a proteomic data mining study that identified it as a kinetochore protein that interacts with p31 comet (16). The direct binding of TRIP13 to p31 comet has been validated and the possibility has been raised that TRIP13 may facilitate p31 cometmediated checkpoint silencing (16).…”

“…A different function of TRIP13 has been suggested by a proteomic data mining study that identified it as a kinetochore protein that interacts with p31 comet (16). The direct binding of TRIP13 to p31 comet has been validated and the possibility has been raised that TRIP13 may facilitate p31 cometmediated checkpoint silencing (16). Our identification of the ATP-dependent factor that disassembles Cdc20-Mad2 subcomplex as TRIP13, along with the previously known interaction of TRIP13 with p31 comet , raised the question of whether p31 comet is required for the disassembling activity of this AAA-ATPase.…”

“…An ATP-dependent disassembly factor was isolated and identified as Thyroid Receptor Interacting Protein 13 (TRIP13), an AAA-ATPase that had been found to interact with p31 comet (16). Furthermore, we then found that the joint action of TRIP13 and p31 comet also promotes MCC disassembly, releases APC/C from checkpoint inhibition, and inactivates the mitotic checkpoint.…”