CLONING AND BACULOVIRUS EXPRESSION OF A DESICCATION STRESS GENE FROM THE BEETLE, TENEBRIO-MOLITOR

The cDNA sequence encoding a novel desiccation stress protein (dsp28) found in the hemolymph of the common yellow mealworm beetle, Tenebrio molitor, has been determined, The sequence encodes a 225 amino acid pr otein containing a 20 amino acid signal peptide, Dsp28 shows no signif icant similarity to any known nucleic acid or protein sequence. Levels of dsp28 mRNA were found to increase approx 5-fold following desiccat ion. Dsp28 cDNA has been cloned into a baculovirus expression vector a nd the expressed protein was compared to native dsp28, Both dsp28 expr essed by recombinant baculovirus and native dsp28 are glycosylated and N-terminally processed, Although dsp28 is induced by cold in addition to desiccation stress, it does not contribute to the freezing point d epression (thermal hysteresis) observed in Tenebrio hemolymph.