Figure 1

Schematic representation of the collagen type VI (ColVI) intracellular assembly process, and interactions with skeletal muscle extracellular matrix (ECM) components. Individual α(VI) chains fold through their triple helical domains to form monomers (1:1:1 ratio) in the endoplasmic reticulum (ER), which further align in an anti-parallel manner as dimers and tetramers that are stabilized by disulfide bonds between cysteine residues (S = S links). Post-translational modifications (indicated in orange) take place in the ER and Golgi, followed by secretion of tetramers that align non-covalently end to end, to form beaded microfibrils in the ECM. ColVI interacts with collagenous and non-collagenous components of the basal lamina and interstitial matrix surrounding muscle fibers.