negative regulation of nucleobase-containing compound metabolic process / negative regulation of small molecule metabolic process / GDP-mannose pyrophosphorylase complex / mannose-1-phosphate guanylyltransferase / negative regulation of phosphate metabolic process / negative regulation of biosynthetic process / mannose-1-phosphate guanylyltransferase (GTP) activity / GDP-mannose metabolic process / GDP-mannose biosynthetic process from mannose / skeletal muscle organ development ...negative regulation of nucleobase-containing compound metabolic process / negative regulation of small molecule metabolic process / GDP-mannose pyrophosphorylase complex / mannose-1-phosphate guanylyltransferase / negative regulation of phosphate metabolic process / negative regulation of biosynthetic process / mannose-1-phosphate guanylyltransferase (GTP) activity / GDP-mannose metabolic process / GDP-mannose biosynthetic process from mannose / skeletal muscle organ development / Synthesis of GDP-mannose / muscle organ morphogenesis / molecular sensor activity / GDP-mannose biosynthetic process / telencephalon development / motor behavior / neuromuscular process / protein glycosylation / enzyme inhibitor activity / cognition / transferase activity / neuron apoptotic process / GTP binding / enzyme binding / extracellular exosome / metal ion binding / cytosol / cytoplasm 類似検索 - 分子機能
ジャーナル: Nat Struct Mol Biol / 年: 2021 タイトル: Cryo-EM structures of human GMPPA-GMPPB complex reveal how cells maintain GDP-mannose homeostasis. 著者: Lvqin Zheng / Zhe Liu / Yan Wang / Fan Yang / Jinrui Wang / Wenjie Huang / Jiao Qin / Min Tian / Xiaotang Cai / Xiaohui Liu / Xianming Mo / Ning Gao / Da Jia / 要旨: GDP-mannose (GDP-Man) is a key metabolite essential for protein glycosylation and glycophosphatidylinositol anchor synthesis, and aberrant cellular GDP-Man levels have been associated with multiple ...GDP-mannose (GDP-Man) is a key metabolite essential for protein glycosylation and glycophosphatidylinositol anchor synthesis, and aberrant cellular GDP-Man levels have been associated with multiple human diseases. How cells maintain homeostasis of GDP-Man is unknown. Here, we report the cryo-EM structures of human GMPPA-GMPPB complex, the protein machinery responsible for GDP-Man synthesis, in complex with GDP-Man or GTP. Unexpectedly, we find that the catalytically inactive subunit GMPPA displays a much higher affinity to GDP-Man than the active subunit GMPPB and, subsequently, inhibits the catalytic activity of GMPPB through a unique C-terminal loop of GMPPA. Importantly, disruption of the interactions between GMPPA and GMPPB or the binding of GDP-Man to GMPPA in zebrafish leads to abnormal brain development and muscle abnormality, analogous to phenotypes observed in individuals carrying GMPPA or GMPPB mutations. We conclude that GMPPA acts as a cellular sensor to maintain mannose homeostasis through allosterically regulating GMPPB.