Abstract
Two cDNA clones encoding the small proteoglycan II (PG II) of bone were isolated from a lambda gt11 expression library. These clones expressed recombinant protein which was cross-reactive with polyclonal and monoclonal antisera to PG II molecules from several connective tissues. The longest clone, lambda Pg 20 was studied in detail. The clone was shown to encode PG II by hybrid selected translation and immunoprecipitation. Northern analysis showed two species of the PG II message of approximately 1.4 and 1.8 kb. Substantial amounts of PG II message were found in bone, tendon, articular cartilage, skin, smooth muscle and cornea. Trace amounts of message were also detected in liver and brain. Radiolabeled bovine PG II cDNA hybridized to RNA from several other species including the human, rat and chicken. The level of PG II mRNA in chick embryonic fibroblasts was sensitive to transformation by Rous sarcoma virus.