Figure 5.

cGMP-induced pCREB production in primary cultures of ORNs. (A) Western blot analysis of pCREB and CREB in primary cultures of ORNs. Cells were stimulated with 10 μM 8-br-cGMP or 100 μM sodium nitroprusside (SNP). IBMP was applied at 100 μM. Arrows indicate the locations of pCREB and CREB. (B) In vitro phosphorylation of CREB in primary cultures of ORNs. The protein kinases utilized are indicated above the lanes. PKA denotes addition of 300 units of PKA catalytic subunits. “PKG (Lung)” indicates incubation with the α isozyme of PKG purified from bovine lungs. “PKG (Brain)” indicates the addition of PKG purified from rat brain. A total of 2 μM 8-br-cGMP was added to activate PKG. Arrows point to the 43-kDa CREB proteins labeled by ³²P. The molecular mass (in kDa) is indicated at left.