98%
921
2 minutes
20
Sphingolipids are essential lipids in eukaryotic membranes. In humans, the first and rate-limiting step of sphingolipid synthesis is catalyzed by the serine palmitoyltransferase holocomplex, which consists of catalytic components (SPTLC1 and SPTLC2) and regulatory components (ssSPTa and ORMDL3). However, the assembly, substrate processing and regulation of the complex are unclear. Here, we present 8 cryo-electron microscopy structures of the human serine palmitoyltransferase holocomplex in various functional states at resolutions of 2.6-3.4 Å. The structures reveal not only how catalytic components recognize the substrate, but also how regulatory components modulate the substrate-binding tunnel to control enzyme activity: ssSPTa engages SPTLC2 and shapes the tunnel to determine substrate specificity. ORMDL3 blocks the tunnel and competes with substrate binding through its amino terminus. These findings provide mechanistic insights into sphingolipid biogenesis governed by the serine palmitoyltransferase complex.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9812531 | PMC |
http://dx.doi.org/10.1038/s41594-020-00551-9 | DOI Listing |
Microb Pathog
September 2025
Department of Biotechnology, Jamia Millia Islamia (A Central University), New Delhi, 110025, India. Electronic address:
Leishmania donovani is an intracellular protozoan parasite that has successfully evolved to manipulate host macrophages. The exact mechanism by which Leishmania spp evades macrophage function is not fully understood. Recently, several studies have shown that pathogens target host-microRNA to alter cellular pathways for their persistence.
View Article and Find Full Text PDFPLoS One
September 2025
School of Basic Medicine, Heilongjiang University of Chinese Medicine, Harbin, China.
Background: Huanglian Wendan Decoction (HLWDD), a classical traditional Chinese medicine (TCM) formula, has shown therapeutic promise in treating metabolic disorders. However, its underlying mechanisms against non-alcoholic fatty liver disease (NAFLD) remain unclear.
Objective: This study aimed to elucidate the pharmacological mechanisms by which HLWDD ameliorates NAFLD, focusing on its impact on lipid metabolism, gut microbiota, and amino acid regulation.
Int J Exp Pathol
September 2025
Laboratory of Pharmacobiology, State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
Porcine respiratory disease complex (PRDC) is a common syndrome in the modern swine industry worldwide, and its pathogenesis remains unclear to date. Our study aimed to investigate PRDC-induced pulmonary fibrosis and sphingolipid metabolism, and their relationship. Mouse and cell line (A549 and 3D4/21) models exposed to bleomycin and/or transforming growth factor-β1 (TGF-β1) were developed.
View Article and Find Full Text PDFJ Neuromuscul Dis
August 2025
Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
Background: Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disorder that progressively affects motor neurons. Gain-of-function mutations in serine palmitoyltransferase (SPT) genes, notably and , have been linked to juvenile ALS. Here, we describe two childhood-onset ALS cases with distinct SPTLC2 mutations, providing new insights into sphingolipid dysregulation and its role in ALS pathogenesis.
View Article and Find Full Text PDFJ Physiol Biochem
August 2025
Graduate Program in Nutrition Sciences, Hospital Universitário Antônio Pedro, Fluminense Federal University (UFF), Rua Marquês do Paraná nº 303, 4º andar, Niterói, Rio de Janeiro (RJ), 24033 900, Brazil.
Ceramides are sphingolipids formed from fatty acids linked to sphingosine and an amide, which are involved in cellular pathways such as apoptosis, fibrosis, oxidative stress, and inflammation. Six distinct fatty acyl selective ceramide synthases (CerS) produce ceramides. This specific enzymatic modulation can either increase or reduce the production of specific ceramides, which can have either adverse or protective effects, suggesting that enzymatic modulation may serve as a tool for innovative therapy.
View Article and Find Full Text PDF