Identification of a developmentally regulated Trichinella spiralis protein that inhibits MyoD-specific protein: DNA complexes in vitro.

Development of the infective L1 larva of Trichinella spiralis occurs as an intracellular parasite of skeletal muscle and leads to the dedifferentiation of the host cell. A novel Trichinella gene, tsJ5, has been identified from a cDNA library screen for sequences encoding Trichinella proteins related to the myogenic bHLH factors. The tsJ5 gene is developmentally regulated, showing preferential expression in the infective muscle stage larva. The product of the tsJ5 gene is not a bHLH protein but represents a novel protein with properties in common with some myogenic repressors. A recombinant TsJ5 protein affects the formation of MyoD:DNA complexes in vitro.