Premium
Subcellular Localization of Human Myocardial PDE3 Isoforms and Components of cAMP Signaling Pathways
Author(s) -
Khan Faiyaz Ahmad,
Krall Judith,
Vandeput Fabrice,
Shen Weixing,
Manganiello Vincent,
Movsesian Matthew
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.891.3
Subject(s) - gene isoform , chemistry , adenylyl cyclase , cytosol , microbiology and biotechnology , caveolae , phosphodiesterase 3 , phosphodiesterase , membrane , biochemistry , receptor , biology , enzyme , gene
Caveolae‐enriched plasma membrane (PM) fractions from failing heart myocardium are highly enriched in b2‐ARs, b3‐ARs, Gα (i), adenylyl cyclase 5/6 and caveolin‐1, but not b1‐ARs or Gα (s). Approximately 30% of the total PDE3 activity is associated with PM and 70% with internal membrane fractions. PDE3A3 is the dominant PDE3A isoform in PM fractions, while all isoforms of PDE3A (A1‐3) and PDE3B1 are present in internal membranes. On gel filtration chromatography, PDE3 activity in solubilized membrane fractions was partitioned between distinct high molecular weight (HMW) and low molecular weight (LMW) peaks. The HMW peaks likely contain multiprotein complexes, including PDE3A1, PDE3A2, and PDE3B as well as several proteins involved in b‐adrenergic receptor‐mediated signaling, including b1‐AR, b2‐AR, AC5/6 ,PKA‐RII, caveolin‐1, and most of the AKAPs that we tested. PDE3 activity in cytosolic fractions consisted primarily of PDE3A2 and PDE3A3, and eluted only in LMW fractions. PDE3A and SERCA2 were coprecipitated from myocardial membranes using anti‐PDE3A antibodies or cAMP‐agarose beads. These results indicate that PDE3 isoforms in myocardial membranes are likely to incorporate into multiprotein complexes; one such complex might contain PDE3A and SERCA2, , suggesting a key role for PDE3A in the regulation of Ca +2 cycling by sarcoplasmic reticulum.