positive regulation of serine C-palmitoyltransferase activity / regulation of sphingolipid biosynthetic process / multidimensional cell growth / leaf senescence / intracellular sphingolipid homeostasis / photomorphogenesis / serine C-palmitoyltransferase activity / pollen development / serine C-palmitoyltransferase / regulation of programmed cell death ...positive regulation of serine C-palmitoyltransferase activity / regulation of sphingolipid biosynthetic process / multidimensional cell growth / leaf senescence / intracellular sphingolipid homeostasis / photomorphogenesis / serine C-palmitoyltransferase activity / pollen development / serine C-palmitoyltransferase / regulation of programmed cell death / sphingosine biosynthetic process / embryo development ending in seed dormancy / sphingolipid biosynthetic process / vacuole / response to endoplasmic reticulum stress / pyridoxal phosphate binding / response to oxidative stress / defense response to bacterium / endoplasmic reticulum membrane / protein-containing complex binding / apoptotic process / endoplasmic reticulum / membrane 類似検索 - 分子機能
Small subunit of serine palmitoyltransferase-like / Small subunit of serine palmitoyltransferase-like / ORMDL family / ORMDL family / : / Aminotransferase, class-II, pyridoxal-phosphate binding site / Aminotransferases class-II pyridoxal-phosphate attachment site. / Aminotransferase, class I/classII / Aminotransferase class I and II / Pyridoxal phosphate-dependent transferase, small domain ...Small subunit of serine palmitoyltransferase-like / Small subunit of serine palmitoyltransferase-like / ORMDL family / ORMDL family / : / Aminotransferase, class-II, pyridoxal-phosphate binding site / Aminotransferases class-II pyridoxal-phosphate attachment site. / Aminotransferase, class I/classII / Aminotransferase class I and II / Pyridoxal phosphate-dependent transferase, small domain / Pyridoxal phosphate-dependent transferase, major domain / Pyridoxal phosphate-dependent transferase 類似検索 - ドメイン・相同性
Transmembrane protein, putative (DUF3317) / Long chain base biosynthesis protein 1 / ORMDL family protein / Long chain base biosynthesis protein 2a 類似検索 - 構成要素
ジャーナル: Sci Adv / 年: 2023 タイトル: Mechanism of sphingolipid homeostasis revealed by structural analysis of SPT-ORM1 complex. 著者: Peng Liu / Tian Xie / Xinyue Wu / Gongshe Han / Sita D Gupta / Zike Zhang / Jian Yue / Feitong Dong / Kenneth Gable / Somashekarappa Niranjanakumari / Wanyuan Li / Lin Wang / Wenchen Liu / ...著者: Peng Liu / Tian Xie / Xinyue Wu / Gongshe Han / Sita D Gupta / Zike Zhang / Jian Yue / Feitong Dong / Kenneth Gable / Somashekarappa Niranjanakumari / Wanyuan Li / Lin Wang / Wenchen Liu / Ruifeng Yao / Edgar B Cahoon / Teresa M Dunn / Xin Gong / 要旨: The serine palmitoyltransferase (SPT) complex catalyzes the first and rate-limiting step in sphingolipid biosynthesis in all eukaryotes. ORM/ORMDL proteins are negative regulators of SPT that respond ...The serine palmitoyltransferase (SPT) complex catalyzes the first and rate-limiting step in sphingolipid biosynthesis in all eukaryotes. ORM/ORMDL proteins are negative regulators of SPT that respond to cellular sphingolipid levels. However, the molecular basis underlying ORM/ORMDL-dependent homeostatic regulation of SPT is not well understood. We determined the cryo-electron microscopy structure of SPT-ORM1 complex, composed of LCB1, LCB2a, SPTssa, and ORM1, in an inhibited state. A ceramide molecule is sandwiched between ORM1 and LCB2a in the cytosolic membrane leaflet. Ceramide binding is critical for the ORM1-dependent SPT repression, and dihydroceramides and phytoceramides differentially affect this repression. A hybrid β sheet, formed by the amino termini of ORM1 and LCB2a and induced by ceramide binding, stabilizes the amino terminus of ORM1 in an inhibitory conformation. Our findings provide mechanistic insights into sphingolipid homeostatic regulation via the binding of ceramide to the SPT-ORM/ORMDL complex that may have implications for plant-specific processes such as the hypersensitive response for microbial pathogen resistance.