Differential expression and localization of calmodulin‐dependent phosphodiesterase genes during ontogenesis of chick dorsal root ganglion

Abstract

The level and characteristics of 3¢)5¢-cyclic nucleotide phosphodiesterase (PDE) activity in chick dorsal root ganglion (DRG) extracts of 5-day posthatching chicken (P5) and E10 and E18 embryos were studied. At all stages, PDE activity is stimulated by calcium and calmodulin. A 5-fold increase in basal cAMP and cGMP PDE activity is evident from E10 to E18, while from E18 to P5 basal PDE activity remains constant. Ion exchange chromatography elution profile indicates that PDE1 isoforms represent the bulk of the PDE activity present. Inhibition studies were performed in order to distinguish the activity due to PDE1A, B and C. Western blot analysis using anti-mammalian PDE1A, B and C specific antibodies was also performed. Densitometric analysis of the stained bands reveals that PDE1B and PDE1C display a prominent increase between day 10 and day 18 of development (eight-and 3.6 fold, respectively) while a more limited increase (1.6-and 1.5-fold) is observed between E18 and P5;on the other hand PDE1A shows continuously increasing levels throughout development. Immunohistochemical analysis was performed with isoform specific antibodies used for western blot analysis. PDE1A immunoreactivity is found in the cytoplasm and fibers of several neurons differing in size and distributed throughout the ganglion. PDE1B staining is evident on all neurons, however, fibers appear very faintly labelled. All neurons appear stained by PDE1C antibody, although the intensity of immunostaining is always heterogeneous in different neuronal populations: no staining was evident on fibers or in non-neural cells. The distinct spatial and temporal expression patterns of PDE1 isoforms may indicate their different physiological roles in developing and mature chick DRG.

Gene expression and protein localization of calmodulin‐dependent phosphodiesterase during ontogenesis of chick retina

“…To advance new hypotheses, it is essential to study the expression and localization of PDE1 isoforms during retinal development in rats. The only data in the literature on developmental expression of PDE1 genes are on dorsal root ganglia (DRG) of chick embryo (Giorgi et al, 2002). The expression of the three isoforms, A, B, and C, increases monotonically during development, with a major peak close to hatching; the isoform B represents the most well expressed isoform in DRG.…”

“…The eluate was concentrated to 100 μl with a Centricon 30 membrane. PDE1C was purified as previously described (Giorgi et al, 2002; Santone et al, 2006).…”

Gene expression and protein localization of calmodulin‐dependent phosphodiesterase in adult rat retina

“…Monoclonal anticalmodulin antibody was from Upstate (Lake Placid, NY; code 05‐173). The specificity of the antibodies against PDE1B and PDE1A (C‐terminal) has already been reported (Giorgi et al,2002).…”

“…A standard of pure PDE1A was a generous gift of Dr. Randall Kincaid and a standard of PDE1B was partially purified from rat caudate putamen. PDE1C was purified as already described (Giorgi et al,2002).…”

Calmodulin-dependent cyclic nucleotide phosphodiesterase (PDE1) splice variants from bovine cardiac muscle

“…For example, at an identical CaM concentration, bovine heart and eye PDE1 isozymes are stimulated at much lower concentrations of Ca 2+ than bovine brain isozymes. Third, PDE1 isozymes identified with membrane fractions of liver cells (Yamagami and Terayama, 1981;Smoake et al, 1995), spermatozoa (Chaudhry and Casillas, 1988;Lefievre et al, 2002) and dorsal root ganglion neurons (Giorgi et al, 2002) showed that PDE1 can be present in both soluble and particulate forms. Therefore, the existence of multiple forms of PDE1 and their differential roles in heart tissues is not unlikely.…”