ADAPT33, A NOVEL OXIDANT-INDUCIBLE RNA FROM HAMSTER HA-1 CELLS

We have recently chosen to undertake a comprehensive evaluation of the modulation of gene expression by oxidative stress, using mRNA as a ma rker. Our model system is HA-1 hamster fibroblasts, using conditions u nder which we observe an adaptive response. Under these conditions, th e HA-1 cells respond to a minimally toxic ''pretreatment'' dose of hyd rogen peroxide by synthesizing RNAs and proteins that protect them aga inst subsequent exposure to a highly cytotoxic concentration of hydrog en peroxide. Using the differential display technique to screen for mo dulated RNAs, we have recently reported an RNA species, adapt15/gadd7, whose steady-state level is significantly induced by a pretreatment d ose of hydrogen peroxide (D. R. Crawford, G. P. Schools, S. L. Salmon, and R. J. A. Davies (1996) Arch. Biochem. Biophys. 325, 256-264). Her e we report a second induced mRNA, designated adapt33. Two homologous adapt33 mRNAs were revealed by Northern blot hybridization. Both of th ese species were inducible by hydrogen peroxide, and they were sized a t 1.46 and 0.99 kb. These inductions appeared to be dependent upon cal cium, occurred as early as 90 min, and were maximal at 5 h. Cell fract ionation revealed that a significant proportion of adapt33 RNA is asso ciated with active translation. adapt33 is a novel sequence, as determ ined by cloning, sequencing, and GenBank analysis. adapt33 represents a new oxidant-inducible RNA and marker of cellular oxidative stress an d a potential aid in the study, detection, and possible therapy of oxi dant-related disorders. (C) 1996 Academic Press, Inc.