Multiple Alternative Splicing and Differential Expression Pattern of the Glycogen Synthase Kinase-3β (GSK3β) Gene in Goat (Capra hircus)

Glycogen synthase kinase-3β (GSK3β) has been identified as a key protein kinase involved in several signaling pathways, such as Wnt, IGF-Ι and Hedgehog. However, knowledge regarding GSK3β in the goat is limited. In this study, we cloned and characterized the goat GSK3β gene. Six novel GSK3β transcripts were identified in different tissues and designated as GSK3β1, 2, 3, 4, 5 and 6. RT-PCR was used to further determine whether the six GSK3β transcripts existed in different goat tissues. Bioinformatics analysis revealed that the catalytic domain (S_TKc domain) is missing from GSK3β2 and GSK3β4. GSK3β3 and GSK3β6 do not contain the negative regulatory sites that are controlled by p38 MAPK. Furthermore, qRT-PCR and western blot analysis revealed that all the GSK3β transcripts were expressed at the highest level in the heart, whereas their expression levels in the liver, spleen, kidney, brain, longissimus dorsi muscle and uterus were different. These studies provide useful information for further research on the functions of GSK3β isoforms.