title: Cloning and functional identification of two novel BRCA1 splicing variants.
abstract: BRCA1 is an important tumor suppressor gene associated with inherited breast and ovarian cancers. In this investigation, two novel BRCA1 splicing variants were cloned from breast cancer cell line ZR-75-30. These transcripts, named BRCA1-PI21-Delta2-21 and BRCA1-Delta2-14, lacked most exons of full length BRCA1 gene, but maintained the original reading frame. We also demonstrated the presence of BRCA1-PI21-Delta2-21 in several human cell lines. Expression of both variants fused with green fluorescent protein (GFP) showed that they targeted different subcellular compartments in the transfected cells. Viability of the cells expressing both fusion proteins decreased notably compared with the viability of cells expressing only GFP. Fluorescence activated cell sorting assay confirmed that the overexpression of two splicing variants resulted in cell apoptosis. Taken together, the different subcellular localization and cell effects of two BRCA1 splicing variants imply that they can have different biological functions in breast cancer cells. Elucidating the functions of BRCA1 splicing variants would help to understand the exact roles of the BRCA1 gene in tumor suppression.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, PR China. lixiamczj@sina.com
authors.forename: Lixia
authors.initials: L
authors.lastname: Miao
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Cao
authors.forename: Chao
authors.initials: C
authors.lastname: Shen
authors.forename: Meijia
authors.initials: M
authors.lastname: Gu
authors.forename: Wanhong
authors.initials: W
authors.lastname: Liu
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: Congyi
authors.initials: C
authors.lastname: Zheng
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D017209:Apoptosis; D019313:BRCA1 Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D005091:Exons; D005260:Female; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D019313:BRCA1 Protein; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins