The (pro)renin receptor mediates constitutive PLZF-independent pro-proliferative effects which are inhibited by bafilomycin but not genistein

Abstract

The (pro)renin receptor [(P)RR] is crucial for cardio-renal pathophysiology. The distinct molecular mechanisms of this receptor are still incompletely understood. The (P)RR is able to interact with different signalling proteins such as promyelocytic leukemia zinc finger protein (PLZF) and Wnt receptors. Moreover, domains of the (P)RR are essential for V-ATPase activity. V-ATPase- and Wnt-mediated effects imply constitutive, i.e., (pro)renin-independent functions of the (P)RR. Regarding ligand-dependent (P)RR signalling, the role of prorenin glycosylation is currently unknown. Therefore, the aim of this study was to analyse the contribution of constitutive (P)RR activity to its cellular effects and the relevance of prorenin glycosylation on its ligand activity. We were able to demonstrate that high glucose induces (P)RR signal transduction whereas deglycosylation of prorenin abolishes its intrinsic activity in neuronal and epithelial cells. By using siRNA against (P)RR or PLZF as well as the PLZF translocation blocker genistein and the specific V-ATPase inhibitor bafilomycin, we were able to dissect three distinct sub-pathways downstream of the (P)RR. The V-ATPase function is ligand-independently associated with strong pro-proliferative effects whereas prorenin causes moderate proliferation in vitro. In contrast, PLZF per se [i.e., in the absence of (pro)renin] does not interfere with cell number.

Molecular markers of putative spermatogonial stem cells in the domestic cat

“…According to the literature, there are three isoforms of PLZF spanning at 673 (74 kDa), 673 (74 kDa) and 550 (61 kDa) amino acids, respectively (Suliman et al., ). Moreover, PLZF may resolve anywhere from 66 to 97 kDa (Kirsch et al., ; Wang et al., ) owing to posttranscriptional modifications that are known to regulate its specificity and function (Suliman et al., ). Cat testis samples in this study yielded several bands within the expected molecular weights.…”