Phase Separation of MAGI2-Mediated Complex Underlies Formation of Slit Diaphragm Complex in Glomerular Filtration Barrier
Phase Separation of MAGI2-Mediated Complex Underlies Formation of Slit Diaphragm Complex in Glomerular Filtration Barrier
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MAGI2 介导的复合物的相分离是肾小球滤过屏障中狭缝隔膜复合物形成的基础
DOI：
10.1681/asn.2020111590
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发表时间：
2021-07
影响因子：
13.6
通讯作者：
Zhang R
中科院分区：
文献类型：
--
作者：
Zhang H;Lin L;Liu J;Pan L;Lin Z;Zhang M;Zhang J;Cao Y;Zhu J;Zhang R
视觉摘要意义陈述足细胞间的裂隙隔膜在维持肾脏的滤过功能中起着关键作用。在每个狭缝隔膜处，存在对狭缝隔膜完整性和足细胞信号转导至关重要的电子致密连接斑块。然而，狭缝光阑组件背后的分子基础还没有很好地理解。在这里，我们证明了MAGI 2，一个独特的MAGUK家族支架蛋白在狭缝隔膜，可以自主进行液-液相分离。MAGI 2-Dendrin-CD 2AP复合物之间的多价相互作用驱动生理条件下狭缝隔膜凝聚物的形成。重组狭缝隔膜浓缩物可有效富集Nephrin。肾病综合征相关MAGI 2突变干扰裂膈冷凝物形成，导致Nephrin募集受损因此，电子致密狭缝光阑组件可以经由狭缝光阑复合体的相分离形成。裂隙隔是相对的足细胞之间的特化粘附连接，建立了尿蛋白丢失的最终过滤屏障。在每个狭缝隔膜的细胞质插入位点处，有一个电子致密且富含蛋白质的细胞室，其对于狭缝隔膜的完整性和信号转导是必不可少的。编码这种无膜区室组分的基因突变与肾小球疾病有关。然而，分子机制形成的分隔狭缝隔膜组件仍然难以捉摸。方法我们通过生物化学、生物物理学和细胞生物学方法的结合，系统地研究了狭缝光阑中关键组分如MAGI 2、Dendrin和CD 2AP之间的相互作用。结果MAGI 2是MAGUK家族特有的狭缝膜支架蛋白，具有自主的液-液相分离能力。MAGI 2-Dendrin-CD 2AP复合物之间的多价相互作用驱动在生理条件下形成高密度的狭缝隔膜凝聚物。重构的狭缝隔膜冷凝物可以有效地募集Nephrin。肾病综合征相关的MAGI 2突变干扰了裂孔隔膜凝聚物的形成，从而导致Nephrin富集受损。结论狭缝光阑的关键部件（例如，MAGI 2及其复合物）可以自发地进行相分离。重构的狭缝隔膜浓缩物可以富含粘附分子和细胞骨架衔接蛋白。因此，电子致密狭缝隔膜组件可以通过足细胞中狭缝隔膜的核心组分的相分离形成。
Visual Abstract Significance Statement Slit diaphragms between podocytes play a critical role in maintaining the filtration function in kidney. At each slit diaphragm there is an electron-dense junctional plaque crucial for slit diaphragm integrity and podocyte signal transduction. However, the molecular basis underlying slit diaphragm assembly is not well understood. Here, we demonstrate that MAGI2, a unique MAGUK family scaffold protein at slit diaphragm, can autonomously undergo liquid-liquid phase separation. Multivalent interactions among the MAGI2-Dendrin-CD2AP complex drive the formation of the slit diaphragm condensates at physiologic conditions. The reconstituted slit diaphragm condensates can effectively enrich Nephrin. A nephrotic syndrome–associated mutation of MAGI2 interferes with slit diaphragm condensate formation, leading to impaired recruitment of Nephrin. Therefore, the electron-dense slit diaphragm assembly might form via phase separation of the slit diaphragm complex. Background Slit diaphragm is a specialized adhesion junction between the opposing podocytes, establishing the final filtration barrier to urinary protein loss. At the cytoplasmic insertion site of each slit diaphragm there is an electron-dense and protein-rich cellular compartment that is essential for slit diaphragm integrity and signal transduction. Mutations in genes that encode components of this membrane-less compartment have been associated with glomerular diseases. However, the molecular mechanism governing formation of compartmentalized slit diaphragm assembly remains elusive. Methods We systematically investigated the interactions between key components at slit diaphragm, such as MAGI2, Dendrin, and CD2AP, through a combination of biochemical, biophysical, and cell biologic approaches. Results We demonstrated that MAGI2, a unique MAGUK family scaffold protein at slit diaphragm, can autonomously undergo liquid-liquid phase separation. Multivalent interactions among the MAGI2-Dendrin-CD2AP complex drive the formation of the highly dense slit diaphragm condensates at physiologic conditions. The reconstituted slit diaphragm condensates can effectively recruit Nephrin. A nephrotic syndrome–associated mutation of MAGI2 interfered with formation of the slit diaphragm condensates, thus leading to impaired enrichment of Nephrin. Conclusions Key components at slit diaphragm (e.g., MAGI2 and its complex) can spontaneously undergo phase separation. The reconstituted slit diaphragm condensates can be enriched in adhesion molecules and cytoskeletal adaptor proteins. Therefore, the electron-dense slit diaphragm assembly might form via phase separation of core components of the slit diaphragm in podocytes.
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DOI：
10.1074/jbc.m116.745026
发表时间：
2016-11-18
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Ni J;Bao S;Johnson RI;Zhu B;Li J;Vadaparampil J;Smith CM;Campbell KN;Grahammer F;Huber TB;He JC;D'Agati VD;Chan A;Kaufman L
通讯作者：
Kaufman L
影响因子：
7.3
作者：
Kuehn, Julius;Wong, Leo E.;Wienands, Juergen
通讯作者：
Wienands, Juergen
影响因子：
18.2
作者：
Greka A;Mundel P
通讯作者：
Mundel P
影响因子：
15.9
作者：
Verma, R;Kovari, I;Holzman, LB
通讯作者：
Holzman, LB
DOI：
10.1073/pnas.0504166102
发表时间：
2005-07-12
影响因子：
11.1
作者：
Lehtonen, S;Ryan, JJ;Farquhar, MG
通讯作者：
Farquhar, MG