GGCX / VKGC / Vitamin K / VKCFD / Hemophilia B / Warfarin / Carboxylation / Blood Coagulation / Calcium homeostasis / Osteocalcin / MEMBRANE PROTEIN / TRANSFERASE
機能・相同性
機能・相同性情報
response to hydroxyisoflavone / structural constituent of bone / hydroxyapatite binding / peptidyl-glutamate 4-carboxylase / gamma-glutamyl carboxylase activity / negative regulation of testosterone biosynthetic process / negative regulation of bone development / cellular response to zinc ion starvation / response to macrophage colony-stimulating factor / Defective gamma-carboxylation of F9 ...response to hydroxyisoflavone / structural constituent of bone / hydroxyapatite binding / peptidyl-glutamate 4-carboxylase / gamma-glutamyl carboxylase activity / negative regulation of testosterone biosynthetic process / negative regulation of bone development / cellular response to zinc ion starvation / response to macrophage colony-stimulating factor / Defective gamma-carboxylation of F9 / vitamin binding / vitamin K metabolic process / regulation of testosterone biosynthetic process / negative regulation of neurotransmitter secretion / response to vitamin K / regulation of osteoclast differentiation / cellular response to vitamin D / regulation of bone mineralization / type B pancreatic cell proliferation / regulation of bone resorption / osteoblast development / response to vitamin D / response to zinc ion / positive regulation of neurotransmitter secretion / response to gravity / response to testosterone / bone mineralization / RUNX2 regulates osteoblast differentiation / response to mechanical stimulus / Transport of gamma-carboxylated protein precursors from the endoplasmic reticulum to the Golgi apparatus / Gamma-carboxylation of protein precursors / Removal of aminoterminal propeptides from gamma-carboxylated proteins / regulation of cellular response to insulin stimulus / response to glucocorticoid / protein maturation / response to activity / skeletal system development / stem cell differentiation / hormone activity / bone development / brain development / cellular response to growth factor stimulus / protein modification process / Golgi lumen / response to estrogen / cognition / cellular response to insulin stimulus / blood coagulation / osteoblast differentiation / glucose homeostasis / response to ethanol / perikaryon / vesicle / learning or memory / cell adhesion / response to xenobiotic stimulus / endoplasmic reticulum lumen / calcium ion binding / dendrite / endoplasmic reticulum membrane / structural molecule activity / extracellular space / extracellular region / membrane / cytoplasm 類似検索 - 分子機能
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
HL121718
米国
American Heart Association
Established Investigator Award
米国
American Heart Association
Collaborative Sciences Award
米国
W. M. Keck Foundation
Forefront of Science Award
米国
Childrens Discovery Institute of Washington University and St. Louis Childrens Hospital
MCII 2020-854
米国
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
AI158500
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM131008
米国
引用
ジャーナル: Cell Res / 年: 2025 タイトル: Structural insights into the vitamin K-dependent γ-carboxylation of osteocalcin. 著者: Qing Cao / Jianjun Fan / Aaron Ammerman / Samjhana Awasthi / Zongtao Lin / Saimi Mierxiati / Huaping Chen / Jinbin Xu / Benjamin A Garcia / Bin Liu / Weikai Li / 要旨: The γ-carboxylation state of osteocalcin determines its essential functions in bone mineralization or systemic metabolism and serves as a prominent biomarker for bone health and vitamin K nutrition. ...The γ-carboxylation state of osteocalcin determines its essential functions in bone mineralization or systemic metabolism and serves as a prominent biomarker for bone health and vitamin K nutrition. This post-translational modification of glutamate residues is catalyzed by the membrane-embedded vitamin K-dependent γ-carboxylase (VKGC), which typically recognizes protein substrates through their tightly bound propeptide that triggers γ-carboxylation. However, the osteocalcin propeptide exhibits negligible affinity for VKGC. To understand the underlying molecular mechanism, we determined the cryo-electron microscopy structures of VKGC with osteocalcin carrying a native propeptide or a high-affinity variant at different carboxylation states. The structures reveal a large chamber in VKGC that maintains uncarboxylated and partially carboxylated osteocalcin in partially unfolded conformations, allowing their glutamate-rich region and C-terminal helices to engage with VKGC at multiple sites. Binding of this mature region together with the low-affinity propeptide effectively stimulates VKGC activity, similar to high-affinity propeptides that differ only in closely fitting interactions. However, the low-affinity propeptide renders osteocalcin prone to undercarboxylation at low vitamin K levels, thereby serving as a discernible biomarker. Overall, our studies reveal the unique interaction of osteocalcin with VKGC and provide a framework for designing therapeutic strategies targeting osteocalcin-related bone and metabolic disorders.