Subcellular localization and regulation of type-1C and type-5 phosphodiesterases.
We investigated the subcellular localization of PDE5 in in vitro human myometrial cells. We demonstrated for the first time that PDE5 is localized in discrete cytoplasmic foci and vesicular compartments corresponding to centrosomes. We also found that PDE5 intracellular localization is not cell- or species-specific, as it is conserved in different animal and human cells. PDE5 protein levels are strongly regulated by the mitotic activity of the smooth muscle cells (SMCs), as they were increased in quiescent, contractile myometrial cultures, and conditions in which proliferation was inhibited. In contrast, PDE1C levels decreased in all conditions that inhibited proliferation. This mirrored the enzymatic activity of both PDE5 and PDE1C. Increasing cGMP intracellular levels by dbcGMP or sildenafil treatments did not block proliferation, while dbcAMP inhibited myometrial cell proliferation. Together, these results suggest that PDE5 regulation of cGMP intracellular levels is not involved in the control of SMC cycle progression, but may represent one of the markers of the contractile phenotype.
Dolci
Susanna
S
Department of Public Health and Cellular Biology, 2nd University of Rome Tor Vergata, Rome, Italy.
Belmonte
Alessia
A
Santone
Rocco
R
Giorgi
Mauro
M
Pellegrini
Manuela
M
Carosa
Eleonora
E
Piccione
Emilio
E
Lenzi
Andrea
A
Jannini
Emmanuele A
EA
D015106:3',5'-Cyclic-GMP Phosphodiesterases; D000328:Adult; D049109:Cell Proliferation; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D006152:Cyclic GMP / Q000378:metabolism; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D020935:MAP Kinase Signaling System; D009215:Myometrium / Q000166:cytology* / Q000201:enzymology*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D015854:Up-Regulation
D016895:Culture Media, Serum-Free; D047428:Protein Kinase Inhibitors; D048369:MAP Kinase Kinase 1; D010727:Phosphoric Diester Hydrolases; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; C517272:PDE1C protein, human; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human; D006152:Cyclic GMP