Collagen molecules comprised of alpha 1(V)-chains (B-chains): an apparent localization in the exocytoskeleton.

Antibodies specific for alpha 1(V) chains and native collagen molecules containing the alpha 1(V) chain have been used to study the localization of alpha 1(V)-containing molecules in differentiating hyaline cartilage. Immunofluorescence data show that the undifferentiated mesenchyme contains significant quantities of these molecules throughout the cell-rich tissue matrix. Examination of fully differentiated hyaline cartilage reveals a unique staining pattern wherein the immunofluorescent material is restricted to the pericellular matrix within the chondrocyte lacunae. We conclude from these data in conjunction with other evidence that the Type V collagens function as components of an exocytoskeleton for connective tissue cells.