title: Mutation p.S335X in GATA4 reduces its DNA binding affinity and enhances cell apoptosis associated with ventricular septal defect.
abstract: Genetic mutations in GATA4, a transcriptional factor, have been found to cause congenital heart diseases. The underlying mechanism, however, remains largely unknown. We previously reported 7 heterozygous variants in patients with ventricular septal defects (VSD). Here we functionally characterized a de novo mutation p.S335X and demonstrated that this mutation led to the pre-termination of its translation, producing a truncated GATA4 lacking a conservative region at C-terminus. Truncated GATA4 did not disturb its subcellular localization; however, it delayed the cardiomyocyte differentiation in P19cl6 model and prohibited Bcl2 expression that led to apoptosis proved by fragmented genomic DNA and positive TUNEL staining in H9C2 cells. By ChIP assay, we showed that GATA4 without C-terminus reduced its DNA binding affinity and suppressed the expressions of its target genes. These findings suggest that C-terminus of GATA4 is critical to maintain DNA binding, and genetic mutations in this region may affect genes important for myocyte apoptosis and differentiation associated with congenital heart defects.
authors.affiliation: Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, China.
authors.forename: F
authors.initials: F
authors.lastname: Yang
authors.forename: M
authors.initials: M
authors.lastname: Wu
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: G-Y
authors.initials: GY
authors.lastname: Zheng
authors.forename: H-Q
authors.initials: HQ
authors.lastname: Cao
authors.forename: W
authors.initials: W
authors.lastname: Sun
authors.forename: R
authors.initials: R
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: Y-H
authors.initials: YH
authors.lastname: Sheng
authors.forename: X-Q
authors.initials: XQ
authors.lastname: Kong
authors.forename: X-L
authors.initials: XL
authors.lastname: Tian
authors.forename: L
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D002460:Cell Line; D004247:DNA / Q000378:metabolism*; D050991:GATA4 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006345:Heart Septal Defects, Ventricular / Q000235:genetics* / Q000473:pathology*; D006801:Humans; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology*; D011485:Protein Binding; D055550:Protein Stability; D021381:Protein Transport; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D050991:GATA4 Transcription Factor; C484170:GATA4 protein, human; D050505:Mutant Proteins; D004247:DNA