Site-directed mutagenesis of long QT syndrome KCNQ1 gene in vitro.

To construct a polymerase chain reaction (PCR) site-directed mutagenesis of the long QT syndrome KCNQ1 gene in vitro, two sets of primers were designed according to the sequence of KCNQ1 cDNA and a mismatch was introduced into primers. Mutagenesis was performed in a two-step PCR. The amplified fragments from the third PCR which contained the mutation site were sub-cloned into the T-vector pCR2.1. Then, the fragments containing the mutation site was obtained from pCR2.1 using restriction enzymes digestion and inserted into the same restriction site of pIRES₂-EGFP-KCNQ1. The sequencing analysis shows that the mutation site was correct. Mutation from A to G in site 983 of KCNQ1 cDNA was found. Using the Effectene transfection reagent, pIRES₂-EGFP-KCNQ1 (G983A) was transfected into HEK cells successfully. These results may shed light on further functional study of KCNQ1 gene. [ABSTRACT FROM AUTHOR]