The cartilage-derived, C-type lectin (CLECSF1): structure of the gene and chromosomal location

Cartilage is a tissue that is primarily extracellular matrix, the bulk of w hich consists of proteoglycan aggregates constrained within a collagen fram ework. Candidate components that organize the extracellular assembly of the matrix consist of collagens, proteoglycans and multimeric glycoproteins. W e. describe the human gene structure of a potential organizing factor, a ca rtilage-derived member of the C-type lectin superfamily (CLECSF1; C-type le ctin superfamily) related to the serum protein, tetranectin. We show by Nor thern analysis that this protein is restricted to cartilage and locate the gene on chromosome 16q23. We have characterized 10.9 kb of sequence upstrea m of the first exon. Similarly to human tetranectin, there are three exons. The residues that are conserved between CLECSF1 and tetranectin suggest th at the cartilage-derived protein forms a trimeric structure similar to that of tetranectin, with three N-terminal alpha-helical domains aggregating th rough hydrophobic faces. The globular, C-terminal domain that has been show n to bind carbohydrate in some members of the family and plasminogen in tet ranectin, is likely to have a similar overall structure to that of tetranec tin. (C) 1999 Elsevier Science B.V. All rights reserved.