The oligomeric assembly of the phosphodiesterase-5 is a mixture of dimers and tetramers: A putative role in the regulation of function

Cellular redox metabolism is modulated by the distinct localization of cyclic nucleotide phosphodiesterase 5A isoforms

“…MmPDE5A3 dimer is as flexible as MmPDE5A1 dimer and can be as well rigidified by the addition of sildenafil, dithiotreitol and diamide (Figure 1C-D). In these experiments, MmPDE5A1 ran, as already reported, both as multiple tetrameric and dimeric conformations, which we respectively named T1-T3 and D1-D3, according to previous data [22,24] (Figure 1C, lane 1). Consistent with the SEC, MmPDE5A2 and MmPDE5A3 showed only the faster migrating bands, as compared to MmPDE5A1 (Figure 1C, lanes 2-3).…”

“…Their catalytic constants are comparable to each other and with data reported in the literature. Unlike MmPDE5A1, which assembles as both dimers and tetramers [22], we showed that MmPDE5A2 and MmPDE5A3 only assemble as dimers, independently of the presence of effectors, ligands and inhibitors (Figure 1).…”

“…Their catalytic constants are comparable to each other and with data reported in the literature. Unlike MmPDE5A1, which assembles as both dimers and tetramers [22], we showed that MmPDE5A2 and MmPDE5A3 only assemble as dimers, independently of the presence of effectors, ligands and inhibitors (Figure 1). However, the structural flexibility of the dimers is different between MmPDE5A2 and MmPDE5A3, as can be seen in the size exclusion chromatography (SEC) elution profiles and native polyacrylamide gel electrophoresis (PAGE) (Figure 1).…”

“…The three isoforms of MmPDE5A have been individually expressed in K. lactis and purified as previously reported [20,22]. All the three isoforms are active as cGMP hydrolysing enzymes.…”

“…Recently, the MmPDE5A1, A2 and A3 were successfully cloned and expressed in the anaerobic facultative Kluyveromyces lactis yeast under the control of the alcohol dehydrogenase 3 (KlADH3) promoter [20] allowing a thorough characterization of the purified proteins in vitro, and in vivo, both in yeast [21] and in murine cardiomyocytes cells [19]. Our aim was to characterize these isoforms to better understand their role in cell signalling and homeostasis [20][21][22][23]. Indeed, in our previous studies, we found that single copy expression of MmPDE5A1 in Saccharomyces cerevisiae altered the endogenous cAMP/cGMP equilibrium and affected the fermentative-respiratory balance, thus implicitly confirming its modulating role in yeast metabolism [21].…”