The diagram is divided into three main sections: Mechanoprotection and Mechanosignaling, Muscle Development, and Membrane Dynamics. In the Mechanoprotection and Mechanosignaling section, caveolae act as a membrane reservoir to protect muscle during stretch. The Muscle Development section shows caveolae linked to key developmental processes in skeletal muscle, including T-tubule development and maintenance of muscle size. The Membrane Dynamics section illustrates how dysfunction of caveolae affects plasma membrane organization and lipid regulation. Each section includes labeled parts and their relationships, showing the overall structure and flow of the processes involved.
Proposed functions of skeletal muscle caveolae. (i) Mechanoprotection and mechanosignaling: caveolae act as a membrane reservoir to protect muscle during stretch. The flattening and disassembly of caveolae in response to stress/stretch also releases caveolar proteins to mediate other pathways. (ii) Muscle development: caveolae have been linked to key developmental processes in skeletal muscle, including T-tubule development and maintenance of muscle size. During skeletal muscle differentiation, CAV3-positive caveolae are reorganized by Bin1 into ring-shaped membrane assemblies that nucleate nascent T-tubules. These caveolae rings recruit components of the excitation–contraction coupling machinery and promote the maturation of the transverse tubular network, supporting muscle fiber development and function. (iii) Membrane dynamics: Dysfunction of caveolae leading to defects in plasma membrane organization and lipid regulation affects cholesterol trafficking, endocytic pathways, and stabilization of plasma membrane proteins such as dysferlin.