The yeast Pmp3p has a significant role in plasma membrane organization

Abstract

Pmp3p-related proteins are highly conserved proteins that exist in bacteria, yeast, nematodes and plants, and its transcript is regulated in response to abiotic stresses, such as low temperature or high salinity. Pmp3p was originally identified in Saccharomyces cerevisiae, and it belongs to the sensitive to Na + (SNA)-protein family, which comprises four members -Pmp3p/Sna1p, Sna2p, Sna3p and Sna4p. Deletion of the PMP3 gene conferred sensitivity to cytotoxic cations, whereas removal of the other SNA genes did not lead to clear phenotypic effects. It has long been believed that Pmp3p-related proteins have a common and important role in the modulation of plasma membrane potential and in the regulation of intracellular ion homeostasis. Here, we show that several growth phenotypes linked to PMP3 deletion can be modulated by the removal of specific genes involved in sphingolipid synthesis. These genetic interactions, together with lipid binding assays and epifluorescence microscopy, as well as other biochemical experiments, suggest that Pmp3p could be part of a phosphoinositide-regulated stress sensor.

Study of the Plasma Membrane Proteome Dynamics Reveals Novel Targets of the Nitrogen Regulation in Yeast

“…Yeast crude membrane extracts were prepared as previously described (22), except that no dithiothreitol was added. Yeast total cell extracts were prepared as previously described (23), except that cells were resuspended in 200 l of cold homogenization medium (250 mM sorbitol, 50 mM imidazole, 1 mM MgCl 2 , pH 7.5) containing a protease inhibitor mix (1 mM PMSF and 2 g/ml each of leupeptin, aprotinin, antipain, pepstatin, and chymostatin) before breaking. The protein concentration was then determined using Bicinchoninic assay, as previously described (24).…”

“…q-RT-PCR-Total RNA was extracted and analyzed by quantitative real-time PCR as previously described (23). Oligonucleotides designed for real-time PCR are listed in supplemental Table S4.…”

The Role of Signaling via Aqueous Pore Formation in Resistance Responses to Amphotericin B

“…For both Hsp90 and Hsp70, there is evidence of the ability to interact preferentially with lipid raft domains (69,70). It has also been reported that the sphingolipid-binding protein Pmp3, which is highly conserved in fungi, is a potent AmB resistance factor (71,72). Such resistance can be suppressed by the addition of phytosphingosine, a sphingolipid pathway intermediate (73).…”

Molecular characterization and expression analysis of pearl millet plasma membrane proteolipid 3 ( Pmp3 ) genes in response to abiotic stress conditions

“…Pmp3 encode for highly hydrophobic proteins that are embedded in plasma membrane with two putative transmembrane domains and small extracellular and cytoplasmic regions. Pmp3 protein is known to modulate plasma membrane potential to maintain cellular ion homeostasis and helps in survival during salt stress (De Block et al, 2015;Serrano and Rodriguez-Navarro, 2001). It is also suggested that Pmp3 regulates a depolarizing cation and proton leak, reducing sensitivity to salinity and low pH conditions.…”