Rab1-Dependent Gβ1γ2 Trafficking during Muscle Mobilization

Fyn kinase-dependent cellular events were related with skeletal muscle denervation. In the present study, we used a combination of techniques to measure ER stability and the related Gβ1γ2 trafficking following muscle mobilization, and demonstrated a temporally and Fyn-dependent up-regulation of Ca2+ level in the mobilized muscle. In parallel, Fyn activity in ER was gradually decreased, which was accompanied by enhanced PTP1B activity and expressions of ER proteins (calnexin, Grp94, cyclophilin, and Hsp70). Moreover, during muscle mobilization, there was more membrane protein breakdown than protein synthesis, which probably featured robust Gβ1γ2 internalization, and Rab1-dependent transport into ER compartment; the signaling was related to disruption of PI3K-Akt signaling and decrement of muscular functions. Then, Gβ1γ2 trafficking is a key component necessary for the early recovery processes regarding muscle atrophy, which would be the therapeutic consideration for muscle repair and regeneration.