Gene Cloning and Expression Analysis of G Protein αq Subunit from Helicoverpa assulta (Guenée)

The cDNA encoding the G protein αq subunit was isolated from the antennae of Helicoverpa assulta (Guenée) by reverse transcription polymerase chain reaction (RT-PCR) and named as HassGαq. Sequencing analysis showed that the full-length of HassGαq open reading frame (ORF) is 1062 bp, 353 amino acid residues are encoded. The predicted molecular weights (MW) and isoelectric point (PI) are 41.5 kD and 5.15, respectively. HassGαq gene was then constructed into expression vector pGEX-4T-2 for over expression in prokaryotic cells. The SDS-PAGE and Western blot analysis showed that induced by Isopropyl-β-D-Thiogalactoside (IPTG), the GST-HassGαq fusion protein is expressed in Escherichia coli BL21, and its MW was found to be about 66 kD nearly equal to the predicted. In addition, RT-PCR analysis showed that the expressions of HassGαq are not tissue specific.