Molecular cloning and analysis of the protein modules of aggrecans.
The large aggregating chondroitin sulfate proteoglycan of cartilage, aggrecan, has served as a prototype of proteoglycan structure. Molecular cloning has elucidated its primary structure and revealed both known and unknown domains. To date the complete structures of chicken, rat and human aggrecans have been deduced, while partial sequences have been reported for bovine aggrecan. A related proteoglycan, human versican, has also been cloned and sequenced. Both aggrecan and versican have two lectin domains, one at the amino-terminus which binds hyaluronic acid and one at the carboxyl-terminus whose physiological ligand is unknown. Both lectins have homologous counterparts in other types of proteins. Within the aggrecans the keratan sulfate domain may be variably present and also has a prominent repeat in some species. The chondroitin sulfate domain has three distinct regions which vary in their prominence in different species. The complex molecular structure of aggrecans is consistent with the concept of exon shuffling and aggrecans serve as suitable prototypes for comprehending the evolution of multi-domain proteins.
Upholt
W B
WB
Department of BioStructure and Function, School of Dental Medicine, University of Connecticut Health Center, Farmington 06030-3705.
Chandrasekaran
L
L
Tanzer
M L
ML
D053674:Aggrecans; D000595:Amino Acid Sequence; D000818:Animals; D011508:Chondroitin Sulfate Proteoglycans / Q000737:chemistry / Q000235:genetics; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D016326:Extracellular Matrix Proteins; D006801:Humans; D037181:Lectins, C-Type; D008969:Molecular Sequence Data; D011509:Proteoglycans / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D053675:Versicans
C508321:Acan protein, rat; D053674:Aggrecans; D011508:Chondroitin Sulfate Proteoglycans; D016326:Extracellular Matrix Proteins; D037181:Lectins, C-Type; D011509:Proteoglycans; C508322:VCAN protein, human; C508324:Vcan protein, rat; D053675:Versicans; D004247:DNA