Expression and Postmortem Proteolysis of Cytoskeletal Protein Talin in Chicken Meat

Abstract

The cytoskeletal protein talin acts as an essential link between integrins and the actin cytoskeleton in costameres. Some studies have reported that talin may contribute to the water-holding capacity of aged meat. Talin has two isoforms, talin1 (T1) and talin2 (T2), but their respective biological roles are not fully understood. Furthermore, the specific roles of T1 and T2 in determining meat quality are unclear. In this study, we analyzed the expression of T1 and T2 in the pectoralis major, biceps femoris, gizzard, and heart in chickens. Additionally, we examined the postmortem changes in talin in the biceps femoris. Expression of T1 mRNA was significantly higher while that of T2 was significantly lower in the gizzard than in the pectoralis major (P < 0.01). Expression of T1 in the gizzard was also signifi cantly higher than in the biceps femoris and heart (P < 0.01). In western blotting using 8d4, anti-talin2 or TA205 antibody, only anti-talin2 could detect talin in the pectoralis major and biceps femoris. Microscopy also showed that talin labeled by anti-talin2, but not 8d4 was located around muscle fibers in the biceps femoris. Furthermore, intact talin band labeled by anti-talin2 within chicken biceps femoris muscle was rapidly diminished during postmortem storage. Our findings propose that the degradation of T2, but not T1, in chicken skeletal muscle may influence the quality of chicken meat.