Colocalization of α‐subunit of Gq protein with actin filaments in L8E63 cells

Abstract

The present study investigated the cellular localization of α‐subunit of Gq (Gαq) protein in developing L8E63, rat skeletal muscle cell line. The colocalization of Gαq with actin cytoskeleton was demonstrated by double‐labeling experiments. In mononucleated myoblasts, the immune‐fluorescence staining pattern of Gαq was almost identical with that of F‐actin visualized with rhodamine‐conjugated phalloidin. However, this colocalization of Gαq with cytoskeleton was not maintained in multinucleated myotubes. The staining pattern of Gαq in myotubes did not match with any specific subcellular structure, but appeared as a uniformly distributed diffuse staining throughout the whole cell surface. Interestingly, change in the expression level of Gαq was not detected during myoblast differentiation, suggesting that actin‐associated Gαq protein might dissociate from the cytoskeleton as cells differentiate. Immunocytochemical experiments using specific antibodies directed against several G proteins indicated that the subcellular localizations of Gαi1, Gαi2, Gαi3, and Gαo were different from those obtained with Gαq.

Key words:

• Gαq
• F‐actin
• Colocalization
• L8E63
• Differentiation
• Immunofluorescence

Notes

To whom correspondence should be addressed. Tel: [phone], Fax: [phone]