BUB1B
Overview
BUB1B (BUB1 Mitotic Checkpoint Serine/Threonine Kinase B, also known as BUBR1) encodes a key component of the spindle assembly checkpoint (SAC), which monitors kinetochore-microtubule attachment and prevents premature anaphase onset. Germline loss-of-function mutations cause mosaic variegated aneuploidy (MVA) syndrome. In cancer, BUB1B mutations or reduced expression contribute to chromosomal instability.
Alterations observed in the corpus
- Low-frequency (1%) mitotic-checkpoint/cell-cycle hit in pediatric rhabdomyosarcoma (RMS); identified alongside CCND1, CCND2, and FOXM1 as mitotic-checkpoint/cell-cycle gene-group alterations in a comprehensive genomic landscape study of 258 RMS samples PMID:24436047
Cancer types (linked)
- Rhabdomyosarcoma (RMS): somatic alteration in ~1% of cases; part of the mitotic-checkpoint gene group; predominantly in PAX-fusion-negative RMS based on the study’s overall cohort composition PMID:24436047
Co-occurrence and mutual exclusivity
- Part of the mitotic-checkpoint/cell-cycle gene group with CCND1, CCND2, and FOXM1 in RMS; broader context of low overall mutation rate (~0.1 protein-coding changes/Mb) in pediatric solid tumors PMID:24436047
Therapeutic relevance
- No targeted therapy data specific to BUB1B-mutant RMS. BUB1B loss-of-function promotes chromosomal instability and may sensitize tumors to agents targeting aberrant mitosis PMID:24436047
Open questions
- The low frequency (1%) limits statistical power to determine whether BUB1B mutations are true drivers or passengers in RMS; functional studies in pediatric sarcoma models are lacking PMID:24436047
Sources
This page was processed by crosslinker on 2026-05-09.