CHARACTERIZATION OF BOVINE ANKYRIN AND SOCS BOX PROTEIN 15 (ASB15)

¹ Purdue University, 915 W. State Street, West Lafayette, IN, 47907-2054, USA

We report the complete bovine ASB15 coding sequence, characterization of the bovine genomic locus, chromosomal localization, and mRNA expression for in vivo and cell culture models. A cDNA clone (2842 bp) containing a full-length coding sequence was obtained by 5’ and 3’ Rapid Amplification of cDNA Ends. Further evaluation of the sequence identified a single ankyrin repeat and SOCS box motif at 327 and 1605 bp of the coding region, respectively. Genomic organization was determined through probing and subcloning from a bovine BAC library identifying intron/exon boundaries. Chromosome localization to bovine chromosome 4 was determined using radiation hybrid and somatic cell mapping panels. Regulation of Asb15 mRNA expression in response to various anabolic compounds was determined in rats. Thirteen 7-wk-old female rats were randomly assigned to each of four treatment groups including: control, clenbuterol, trenbolone acetate, and growth hormone. Changes in Asb15 mRNA expression were measured at 30 min, 12 h, and 24 h following intraperitoneal injections of each compound (50g/kg). Clenbuterol treatment decreased Asb15 mRNA expression in skeletal muscle at 12 and 24 h (P < 0.01) and also decreased mRNA expression in lung at 12h (P < 0.05). Expression of Asb15 mRNA was also measured in C2C12 myoblasts (day 0) and 1, 3, 5, and 7 days after induction of differentiation. Asb15 mRNA expression increased with differentiation of myoblast to myotubes when compared to day 0 myoblasts (P < 0.01).