Localization of BRCA1 protein at the cellular level.
Based on its amino acid sequence and the existence of three nuclear localization signal (NLS)3 regions, BRCA1 is likely to be a cell cycle-dependent nuclear protein, regulated by cyclin-dependent kinases (cdk) and associated with nuclear proteins such as Rad51 and BARD1, involved in transcription regulation and participating in DNA replication checkpoints. However, many authors have also described a cytoplasmic expression pattern. Moreover, BRCA1 was present not only in a dot like pattern in the nucleus but also associated with a channel-like system of cytoplasm and endoplasmic reticulum invaginating into the nucleus. BRCA1 expression patterns can also be influenced by alternative splice variants and by cell cycle-dependent expression level and localization. Further ultrastructural and confocal studies using C-terminal antibodies, that do not react with C-terminal truncated form of BRCA1 should shed new light upon the exact localization of BRCA1.
De Potter
C R
CR
Department of Pathology, University Hospital, Gent, Belgium. christian.depotter@rug.ac.be
Coene
E D
ED
Schelfhout
V R
VR
D017398:Alternative Splicing; D019313:BRCA1 Protein / Q000032:analysis*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D004261:DNA Replication; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005786:Gene Expression Regulation; D019398:Genes, BRCA1; D006801:Humans; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology
D019313:BRCA1 Protein