We have recently shown that nitric oxide activates the beta2 subunit of soluble guanylyl cyclase. In the present study, we show developmental regulation of this subunit. Analysis of mRNA expression by RT-PCR and RNase protection analysis in kidneys revealed no expression of the beta2 subunit in neonatal and strong expression in adult rats. A reciprocal regulation with much lower expression levels was observed in rat lung. Further examination of kidneys from 3, 6, 16, 22, 25, 31 and 36-day-old rats showed that significant expression appears between postnatal day 16 and 22. Isolation of the rat beta2 promoter by genome walking and cloning into a reporter gene vector showed promoter activity for the sense but not the antisense construct providing an in vitro assay for further analysis of the developmental beta2 subunit regulation.
