A putative NEM1 homologue regulates lipid droplet biogenesis via PAH1 in Tetrahymena thermophila

Abstract

Nuclear envelope morphology protein 1 along with a phosphatidate phosphatase regulates lipid homeostasis and membrane biogenesis in yeast and mammals. We investigated four putative homologues and ) in the genome. Disruption of or did not compromise normal cell growth. In contrast, we were unable to generate knockout strain of under the same conditions, indicating that is essential for growth. Interestingly, loss of TtNEM1B but not TtNEM1C or TtNEM1D caused a reduction in lipid droplet number. Similar to yeast and mammals, TtNem1B of Tetrahymena exerts its function via Pah1, since we found that PAH1 overexpression rescued loss of Nem1 function. However, unlike NEM1 in other organisms, does not regulate ER/nuclear morphology. Similarly, neither TtNEM1C nor TtNEM1D is required to maintain normal ER morphology. While Tetrahymena PAH1 was shown to functionally replace yeast earlier, we observed that homologues did not functionally replace yeast NEM1. Overall, our results suggest the presence of a conserved cascade for regulation of lipid homeostasis and membrane biogenesis in . Our results also suggest a Nem1-independent function of Pah1 in the regulation of ER morphology in.

Towards a circular economy: fabrication and characterization of biodegradable plates from sugarcane waste

“…Bacillus species are spore-forming, rod-shaped, Grampositive, aerobic or facultative anaerobic bacteria that are abundant in soil and are thought to be incredibly helpful microbes for the production of antimicrobial compounds (Amin et al, 2012). According to Thakaew and Niamsup (2013) and Shukla et al (2018Shukla et al ( ), 10.3389/fsufs.2023 Frontiers in Sustainable Food Systems 08 frontiersin.org B. subtilis is regarded as a key biocontrol agent for a number of mycotoxigenic and pathogenic fungi. In this investigation, two chosen strains of Bacillus subtilis and Aspergillus niger were evaluated in bagasse plates in the Intertek lab.…”

The Phosphatase Cascade Nem1/Spo7-Pah1 Regulates Fungal Development, Lipid Homeostasis, and Virulence in Botryosphaeria dothidea

“…In Cryptococcus neoformans , which causes life-threatening meningoencephalitis mainly in immunocompromised patients, the genome-wide functional analysis of phosphatases revealed that Nem1 plays important roles in melanin production, multiple stresses responses, and virulence ( 28 ). Tetrahymena thermophila contains four Nem1 homologues, which are in involved in regulating LD biogenesis via Pah1 ( 29 ). NEP1-R1 (Spo7 homologue) knockdown in Caenorhabditis elegans embryos results in twinned nuclei, similar to depletion of C. elegans CTDNEP1 (Nem1 homologue) ( 30 ).…”

NLIP and HAD-like Domains of Pah1 and Lipin 1 Phosphatidate Phosphatases Are Essential for Their Catalytic Activities

“…The conserved Trp-637 within the WRDPLVDID domain of Pah1 is non-essential for the PAP activity but is required for its functions in vivo [ 9 ]. Pah1 PAP activity plays important roles in the formation of lipid droplets [ 10 , 11 , 12 , 13 ], and maintains vacuole homeostasis and membrane fusion [ 14 ]. Altering lipid metabolism by eliminating Pah1 PAP activity shows some potential biotechnological applications such as increased β-carotene production in Saccharomyces cerevisiae [ 15 ], enhanced triterpenoid production [ 16 ], and membrane protein expression [ 17 ] in Yarrowia lipolytica.…”

“…Tetrahymena thermophila Pah/Lipin homologs are encoded by TtPAH1 and TtPAH2 genes [ 12 , 43 ]. In terms of protein primary structure, TtPah1 protein is about 96 kDa which is comparable to yeast Pah1 and human Lipin 1, whereas TtPah2 is a low molecular weight protein of 37 kDa with fused NLIP and HAD-like conserved domains [ 43 ].…”