Molecular mechanism of endosomal sorting of growth factors and receptors

生长因子和受体内体分选的分子机制

基本信息

批准号：
15370053
负责人：
KITAMURA Naomi
金额：
$ 9.79万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15370053/
关键词：
growth factor growth factor receptor early endosome sorting Hrs STAM deubiquitinating enzyme UBPY ALG-2 ユビキチン化 STAM Alix

项目摘要

Upon stimulation with growth factors, their receptors are rapidly internalized as a complex with bound ligands, and are transported to the endosome. From the endosome, ligand-bound receptors are transported to the lysosome for degradation. In this study, we examined the molecular mechanisms how Hrs and STAM regulate the endosomal sorting of growth factor/receptor complexes, and obtained the following results.1.STAM mutants lacking the Hrs-binding activity were defective in causing the enlargement of early endosomes, accumulating ubiquitinated proteins on this aberrant organelle, and inhibiting the degradation of ligand-activated epidermal growth factor receptors(EGFR). These results indicate that association with Hrs on the early endosome is a prerequisite for STAM function.2.Overexpression of a deubiquitinating enzyme UBPY that is a STAM binding protein, reduced the ubiquitination level of EGFR and delayed its degradation in EGF-stimulated cells. In contrast overexpression of a catalytically-inactive UBPY mutant did not show such effects. These results indicate that UBPY plays an important role through reduction of the ubiquitination level of EGFR in regulation of EGFR sorting.3.ALG-2 was identified as a novel Hrs-binding protein by a yeast two-hybrid screening. Hrs, ALG-2 and an ALG-2 binding protein Alix were bound in a Ca^<2+>-dependent manner. Treatment of cells with a Ca^<2+> ionophore induced colocalization of these proteins to the early endosome. These results suggest that Hrs regulates endosomal sorting by recruiting Alix through ALG-2 to the early endosome in a Ca^<2+>-dependent manner.

在生长因子刺激后，它们的受体迅速内化为与结合配体的复合物，并被转运至内体。配体结合受体从内体转运至溶酶体进行降解。本研究探讨了Hrs和STAM调节生长因子/受体复合物的内体分选的分子机制，并得到以下结果：1.缺乏Hrs结合活性的STAM突变体不能引起早期内体的增大，在这个异常的细胞器上积累泛素化蛋白，并抑制配体激活的表皮生长因子受体（EGFR）的降解。这些结果表明，早期内体上Hrs的结合是STAM功能的先决条件。2.STAM结合蛋白去泛素化酶UBPY的过度表达，降低了EGFR的泛素化水平，延缓了EGF刺激细胞的降解。相反，催化失活的 UBPY 突变体的过度表达没有显示出这样的效果。这些结果表明UBPY通过降低EGFR的泛素化水平在EGFR分选的调控中发挥重要作用。3.酵母双杂交筛选将ALG-2鉴定为一种新型的Hrs结合蛋白。小时，ALG-2和ALG-2结合蛋白Alix以Ca 2+ 依赖性方式结合。用Ca 2+ 离子载体处理细胞诱导这些蛋白质共定位至早期内体。这些结果表明，Hrs通过ALG-2以Ca 2+ 依赖性方式将Alix募集到早期内体来调节内体分选。

项目成果

期刊论文数量（44）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Activation of c-Met (hepatocyte growth factor receptor) in human gastric cancer tissue

DOI：
10.1111/j.1349-7006.2004.tb02185.x
发表时间：
2004-10-01
期刊：
CANCER SCIENCE
影响因子：
5.7
作者：
Inoue, T;Kataoka, H;Miyazawa, K
通讯作者：
Miyazawa, K

K.Nakano: "Cofilin phosphorylation and actin polymerization by NRK/NESK, a member of the germinal center kinase family"Exp.Cell Res.. 287. 219-227 (2003)

K.Nakano：“生发中心激酶家族成员 NRK/NESK 的肌动蛋白丝切蛋白磷酸化和肌动蛋白聚合”Exp.Cell Res.. 287. 219-227 (2003)

DOI：
发表时间：
期刊：
影响因子：
0
作者：
通讯作者：

A scaffold protein JIP-1b enhances amyloid precursor protein phosphorylation by JNK and its association with kinesin light chain 1

DOI：
10.1074/jbc.m212160200
发表时间：
2003-06-20
期刊：
JOURNAL OF BIOLOGICAL CHEMISTRY
影响因子：
4.8
作者：
Inomata, H;Nakamura, Y;Kitamura, N
通讯作者：
Kitamura, N

STAM protein bind ubiquitinated proteins on the early endosome via the VHS domain and ubiquitin-interacting motif

STAM 蛋白通过 VHS 结构域和泛素相互作用基序结合早期内涵体上的泛素化蛋白

DOI：
发表时间：
2003
期刊：
Mol.Biol.Cell 14
影响因子：
0
作者：
Matsumoto;M.;Yada;M.;Hatakeyama;S.;Ishimoto;H.;Tanimura;T.;Tsuji;S.;Kakizuka;A.;Kitagawa;M.;Nakayama;K.I.;E.Mizuno
通讯作者：
E.Mizuno

Enhanced JNK activation by NESK without kinase activity upon caspase-mediated cleavage during apoptosis