Alternate splicing of dysferlin C2A confers Ca²⁺-dependent and Ca²⁺-independent binding for membrane repair

Structure. 2014 Jan 7;22(1):104-15. doi: 10.1016/j.str.2013.10.001. Epub 2013 Nov 14.


Dysferlin plays a critical role in the Ca²⁺-dependent repair of microlesions that occur in the muscle sarcolemma. Of the seven C2 domains in dysferlin, only C2A is reported to bind both Ca²⁺ and phospholipid, thus acting as a key sensor in membrane repair. Dysferlin C2A exists as two isoforms, the "canonical" C2A and C2A variant 1 (C2Av1). Interestingly, these isoforms have markedly different responses to Ca²⁺ and phospholipid. Structural and thermodynamic analyses are consistent with the canonical C2A domain as a Ca²⁺-dependent, phospholipid-binding domain, whereas C2Av1 would likely be Ca²⁺-independent under physiological conditions. Additionally, both isoforms display remarkably low free energies of stability, indicative of a highly flexible structure. The inverted ligand preference and flexibility for both C2A isoforms suggest the capability for both constitutive and Ca²⁺-regulated effector interactions, an activity that would be essential in its role as a mediator of membrane repair.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alternative Splicing*
  • Amino Acid Sequence
  • Animals
  • Calcium / metabolism*
  • Cell Line
  • Crystallography, X-Ray
  • Dysferlin
  • Humans
  • Membrane Proteins / chemistry*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Models, Molecular
  • Molecular Sequence Data
  • Muscle Proteins / chemistry*
  • Muscle Proteins / genetics
  • Muscle Proteins / metabolism
  • Mutagenesis, Site-Directed
  • Myoblasts / cytology
  • Myoblasts / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Regeneration
  • Sarcolemma / metabolism*
  • Sarcolemma / ultrastructure
  • Thermodynamics


  • DYSF protein, human
  • Dysf protein, mouse
  • Dysferlin
  • Membrane Proteins
  • Muscle Proteins
  • RNA, Messenger
  • Recombinant Proteins
  • Calcium