AHNAK1 and AHNAK2 are costameric proteins: AHNAK1 affects transverse skeletal muscle fiber stiffness


  • A. Marg
  • H. Haase
  • T. Neumann
  • M. Kouno
  • I. Morano


  • Biochemical and Biophysical Research Communications


  • Biochem Biophys Res Commun 401 (1): 143-148


  • The AHNAK scaffold PDZ-protein family is implicated in various cellular processes including membrane repair; however, AHNAK function and subcellular localization in skeletal muscle are unclear. We used specific AHNAK1 and AHNAK2 antibodies to analyzed the detailed localization of both proteins in mouse skeletal muscle. Co-localization of AHNAK1 and AHNAK2 with vinculin clearly demonstrates that both proteins are components of the costameric network. In contrast, no AHNAK expression was detected in the T-tubule system. A laser wounding assay with AHNAK1-deficient fibers suggests that AHNAK1 is not involved in membrane repair. Using Atomic Force Microscopy (AFM), we observed a significantly higher transverse stiffness of AHNAK1-/- fibers. These findings suggest novel functions of AHNAK proteins in skeletal muscle.