National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
F32GM142137
米国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2023 タイトル: activates hydrolysis by recruiting and orienting on the membrane surface. 著者: Maria E Falzone / Roderick MacKinnon / 要旨: catalyze the hydrolysis of phosphatidylinositol 4, 5-bisphosphate [Formula: see text] into [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text]. [Formula: see text] ... catalyze the hydrolysis of phosphatidylinositol 4, 5-bisphosphate [Formula: see text] into [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text]. [Formula: see text] regulates the activity of many membrane proteins, while and lead to increased intracellular Ca levels and activate protein kinase C, respectively. are regulated by G protein-coupled receptors through direct interaction with [Formula: see text] and [Formula: see text] and are aqueous-soluble enzymes that must bind to the cell membrane to act on their lipid substrate. This study addresses the mechanism by which [Formula: see text] activates 3. We show that 3 functions as a slow Michaelis-Menten enzyme ( [Formula: see text] ) on membrane surfaces. We used membrane partitioning experiments to study the solution-membrane localization equilibrium of 3. Its partition coefficient is such that only a small quantity of 3 exists in the membrane in the absence of [Formula: see text] . When [Formula: see text] is present, equilibrium binding on the membrane surface increases 3 in the membrane, increasing [Formula: see text] in proportion. Atomic structures on membrane vesicle surfaces show that two [Formula: see text] anchor 3 with its catalytic site oriented toward the membrane surface. Taken together, the enzyme kinetic, membrane partitioning, and structural data show that [Formula: see text] activates by increasing its concentration on the membrane surface and orienting its catalytic core to engage [Formula: see text] . This principle of activation explains rapid stimulated catalysis with low background activity, which is essential to the biological processes mediated by [Formula: see text], and .
履歴
登録
2022年9月28日
登録サイト: RCSB / 処理サイト: RCSB
改定 1.0
2023年5月24日
Provider: repository / タイプ: Initial release
改定 1.1
2024年6月19日
Group: Data collection / カテゴリ: chem_comp_atom / chem_comp_bond
改定 1.2
2024年9月25日
Group: Data collection / Source and taxonomy カテゴリ: em_admin / em_entity_assembly_naturalsource / em_entity_assembly_recombinant Item: _em_admin.last_update / _em_entity_assembly_naturalsource.id / _em_entity_assembly_recombinant.id
包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES 詳細: Gbg was reconstituted at 1:15 (wt/wt). Final lipid concentration was 17.5 mM. PLCb3 concentration was 0.5 mg/mL