Molecular cloning of a novel retinoic acid-responsive gene, HA1R-62, whichis also up-regulated in Hoxa-1-overexpressing cells

Using a PCR-based cDNA subtractive hybridization method (L. Diatchenko et a t, Proc. Natl, Acad, Sci, USA, 93: 6025-6030, 1996), we cloned a cDNA fragm ent of a novel gene that is highly expressed in F9-10; F9-10 is an F9 terat ocarcinoma stem cell line that expresses high levels of exogenous Hoxa-1 mR NA and protein in comparison to F9 wild-type stem cells, which do not expre ss endogenous Hoxa-1 mRNA in the absence of retinoic acid (RA), Rapid ampli fication of cDNA ends was used to clone the full-length cDNA of this gene, designated HA1R-62 (Hoxa1 regulated-62), We have shown that HA1R-62 is also a RA-responsive gene and that it is expressed (mRNA size, similar to 4.3 k b) in adult mouse thymus, lung, kidney, and ovary as well as in 12.5-day mo use embryos. DNA sequence analysis and in vitro translation experiments hav e shown that HA1R-62 encodes a protein with a molecular mass of approximate ly 26 kDa, Elucidation of the function of the HA1R-62 gene product will pro vide new insights into the functions of RA and homeobox genes.