J. Biol. Chem., Vol. 261, Issue 15, 6654-6657, 05, 1986
Alpha 1 type IV collagen gene evolved differently from fibrillar collagen genes
Y Sakurai, M Sullivan and Y Yamada
Type IV collagen is a major structural component in basement membranes. It
is considerably different from the fibrillar collagens, types I-III. For
example, unlike fibrillar collagens, the triple helical domain of type IV
collagen is frequently interrupted by nonhelical regions. In this report,
we demonstrate several overlapping genomic clones which cover most of the
mouse alpha 1(IV) chain. Electron microscopic analysis of R-loops revealed
that there were at least 28 exons within 35 kilobases of the gene segment.
The sizes of six exons were determined by DNA sequence analysis to be 81,
178, 134, 73, 129, and 213 base pairs. These sizes do not appear to be
related to the 54-base pair coding unit which is characteristic of
fibrillar collagen exons, suggesting that the alpha 1 type IV collagen gene
evolved differently from the fibrillar collagen genes.