研究揭示WLS/Evi介導Wnt轉運和分泌的結構基礎
作者:
小柯機器人發布時間:2020/12/25 15:15:55
美國哥倫比亞大學Filippo Mancia、杜克大學David M. Virshup等研究人員合作揭示WLS/Evi介導Wnt轉運和分泌的結構基礎。這一研究成果於2020年12月23日在線發表在國際學術期刊《細胞》上。
研究人員表示,Wnt是進化保守的配體,可在短距離內發出信號來調節形態發生、細胞命運和幹細胞更新。Wnt分泌的第一步和必不可少的步驟是它們的O-棕櫚油酸化,隨後將其裝載到專用轉運蛋白Wntless/evennessinterrupted(WLS/Evi)上。
研究人員報導了與WLS結合的棕櫚油酸化人源WNT8A的3.2Å解析度冷凍電鏡(cryo-EM)結構。研究人員通過生化實驗來探究了這些關聯的生理意義。WLS膜結構域與G蛋白偶聯受體(GPCR)具有緊密的結構同源性。Wnt髮夾插入GPCR樣結構域中保守的疏水腔中,並且棕櫚油酸在兩個螺旋之間突出進入雙層。另一個Wnt髮夾上高度保守殘基的構象轉換可能有助於其轉移至接收細胞。這項工作為動物身體發育計劃和幹細胞生物學的主要機制提供了分子水平的見解。
附:英文原文
Title: Structural Basis of WLS/Evi-Mediated Wnt Transport and Secretion
Author: Rie Nygaard, Jia Yu, Jonathan Kim, Daniel R. Ross, Giacomo Parisi, Oliver B. Clarke, David M. Virshup, Filippo Mancia
Issue&Volume: 2020-12-23
Abstract: Wnts are evolutionarily conserved ligands that signal at short range to regulate morphogenesis,cell fate, and stem cell renewal. The first and essential steps in Wnt secretion aretheir O-palmitoleation and subsequent loading onto the dedicated transporter Wntless/evennessinterrupted (WLS/Evi). We report the 3.2 resolution cryogenic electron microscopy(cryo-EM) structure of palmitoleated human WNT8A in complex with WLS. This is accompaniedby biochemical experiments to probe the physiological implications of the observedassociation. The WLS membrane domain has close structural homology to G protein-coupledreceptors (GPCRs). A Wnt hairpin inserts into a conserved hydrophobic cavity in theGPCR-like domain, and the palmitoleate protrudes between two helices into the bilayer.A conformational switch of highly conserved residues on a separate Wnt hairpin mightcontribute to its transfer to receiving cells. This work provides molecular-levelinsights into a central mechanism in animal body plan development and stem cell biology.
DOI: 10.1016/j.cell.2020.11.038
Source: https://www.cell.com/cell/fulltext/S0092-8674(20)31610-X
Cell:《細胞》,創刊於1974年。隸屬於細胞出版社,最新IF:36.216