MOLECULAR CHARACTERIZATION OF THE NOVEL BASIC HELIX-LOOP-HELIX PROTEIN DEC1 EXPRESSED IN DIFFERENTIATED HUMAN EMBRYO CHONDROCYTES

The differentiation of human embryo chondrocytes was markedly induced by the addition of Bt(2)cAMP to the culture medium. Using this culture system, a novel human cDNA for a basic helix-loop-helix (bHLH) protei n (named DEC1) expressed primarily in the chondrocytes in response to Bt(2)cAMP was cloned by the subtractive hybridization method. DEC1 pro tein consists of 412 amino acids and exhibits structural similarities to the mammalian HES family, Drosophila hairy, and Enhancer of split m 7 in the bHLH region. Northern blot analysis showed that DEC1 mRNA was expressed in various tissues including the cartilage, lung, spleen, a nd intestine, but not in the brain. These findings suggest that the bH LH factor DEC1 is involved in the control of cell differentiation in s everal tissues including cartilage. (C) 1997 Academic Press.