Comment 1) This category currently includes both the major bovine heart and lung forms of CaM-dependent PDEs because an identical cDNA sequence has been obtained from both sources (Sonnenberg et al. J. Biol. Chem. 270:989-1000 (1995)). However, in the original reports of Sharma et al. (J. Biol. Chem. 261:14160-14166 (1986)) the CaM-dependent PDE with a larger molecular weight apparently having calmodulin very tightly bound was reported. Thus it is possible that the major lung and heart enzymes are not identical.

Submitted by J. Beavo, 8/4/97 email: beavo@u.washington.edu