Phosphodiesterase 1C, Calmodulin Dependent (PDE1C)

PDE1C isoforms diverge at their C termini. Northern blot analysis revealed that HCAM3A is expressed as a 5.6-kb mRNA in heart and brain and at lower levels in several other tissues. HCAM3B is expressed as an approximately 10-kb mRNA in brain and heart and, to a lesser extent, in lung. The HCAM3B probe detected additional faint bands. Although expression of full-length HCAM3A and HCAM3B in S. cerevisiae did not result in PDE activity, an amino-truncated HCAM3A gave measurable PDE activity with high affinity for both cAMP and cGMP.consistent with the predicted mass of the PDE1C1 isoform, in human cardiac myocyte lysates. Immunohistochemical analysis of human cardiac myocytes revealed PDE1C1 in a striated pattern, with strong staining of cardiac Z bands and weaker staining of M lines.