OBJECTIVETo perform the functional analysis of a novel H436Y mutation of GATA-4 gene identified in Han Chinese patients with congenital cardiac septal defects.

METHODSUsing bioinformatics to predict if the H436Y mutation in the GATA-4 gene affects its protein function. H436Y mutation in the GATA-4 gene was generated by Quick Change Lightning site-directed mutagenesis kit and verified by DNA sequencing. GATA-4-wt or GATA-4-mut DNA was cotransfected into Hela cells with DNA for the luciferase reporter gene atrial natriuretic factor (ANF), and luciferase activity was measured by an LKB luminometer 48 h after transient transfection.

RESULTSAlignment of the GATA-4 amino acid sequence indicated that the histidine residue at position 436 was conserved, and H436Y mutation in the GATA-4 gene is expected to affect its protein function. The H436Y mutation significantly reduced the transcriptional activation of downstream reporter ANF when compared to wild-type GATA-4 (P<0.01).

CONCLUSIONThe mutation c.1306C-->T of the GATA-4 gene impaired the activation of the downstream target, suggesting that the H436Y mutation in the C-terminal region of the GATA-4 gene might prevent its biological function.