Regulation of Macropinocytosis by Hssh3bp1

Hssh3bp1 对巨胞饮作用的调节

• 批准号: 7081308
• 负责人: LESZEK KOTULA
• 金额: $ 23.51万
• 依托单位: NEW YORK BLOOD CENTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-15 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7081308
• 关键词: binding proteins; biological signal transduction; brain neoplasms; carcinogenesis; cell growth regulation; cell line; clathrin; cytoskeletal proteins; enzyme activity; glioma; growth factor receptors; human genetic material tag; membrane activity; membrane proteins; membrane structure; molecular cloning; neoplastic cell; phosphorylation; pinocytosis; protein localization; protein protein interaction; protein structure function; protein tyrosine kinase; site directed mutagenesis; spectrin; tissue /cell culture

DESCRIPTION (provided by applicant): The long-term goal of this proposal is to understand the structure, function and regulatory processes of the cell membrane skeleton and its involvement in human diseases and particularly in brain tumorigenesis. Recent studies also implicate membrane cytoskeletal proteins in normal brain development and behavior, and proper electrophysiological activity of neurons. Therefore, it is critical to develop a detailed understanding of molecular and cellular processes regulated by membrane cytoskeletal proteins. Membrane skeleton is a multiprotein structure in which spectrin plays a major structural role. Based on its binding properties to alpha spectrin Src homology 3 domain (SH3) we identified a novel protein designated human spectrin S H 3 domain-binding protein 1, or Hssh3bp1. Our recent work suggest that a spectrin-like protein and Hssh3bp1 participate in regulation of macropinocytosis. Macropinocytosis is a type of endocytosis that occurs through vesicles larger than 200 nm and is critical for cellular uptake of fluid and macromolecules. Physiological significance of macropinocytosis is largely unknown but is has been postulated to be involved in immunological responses and cellular uptake of some pathogens. Significantly, cancer cell lines have been demonstrated to up-regulate macropinocytosis in response to growth factor stimulation. Our data indicate that increased Hssh3bp1 expression inhibits macropinocytosis and that Hssh3bp1 expression is abnormally regulated in glioma tumor cell lines. These data support our working hypothesis that Hssh3bp1 inhibits macropinocytosis by opposing growth factor receptor stimulation. The proposed studies focus on determining mechanism of regulatory function of Hssh3bp1 in macropinocytosis using human glioma cell lines as a model system. The function of Hssh3bp1 in macropinocytosis and in cell growth may involve its binding partner, Abl tyrosine kinase. Our mechanistic hypothesis of this research proposal is that tyrosine-phosphorylated Hssh3bp1 inhibits Abl kinase resulting in decreased cell growth due to reduced phosphorylation of multiple mitogenic targets of Abl kinase. Alternatively, Hssh3bp1 binding to Abl in macropinosomes sequesters Abl in cytoplasm, consequently, Abl kinase cannot translocate to the nucleus, a process known to control cell growth. In addition to testing this hypothesis, we will determine whether other proteins known to affect macropinocytosis also regulate Hssh3bp1 phosphorylation and control the Hssh3bp1 function. These studies are likely to lead to novel information regarding molecular regulation of macropinocytosis at the cellular level.

描述(申请人提供)：这项建议的长期目标是了解细胞膜骨架的结构、功能和调控过程，以及它与人类疾病，特别是脑肿瘤发生的关系。最近的研究还表明，膜细胞骨架蛋白与正常的大脑发育和行为以及神经元的适当电生理活动有关。因此，对膜细胞骨架蛋白调控的分子和细胞过程有一个详细的了解是至关重要的。膜骨架是一种多蛋白质结构，其中，血影蛋白起着主要的结构作用。根据其与血影蛋白同源3区的结合特性，我们鉴定了一个新的蛋白质，命名为人血影蛋白S H3结构域结合蛋白1，简称Hssh3bp1。我们最近的工作表明，一个幽灵蛋白样蛋白和Hssh3bp1参与了巨噬细胞吞噬的调节。巨噬细胞吞噬是一种通过大于200 nm的小泡发生的内吞作用，对于细胞对液体和大分子的摄取至关重要。巨噬细胞吞噬症的生理意义尚不清楚，但已被认为与免疫反应和某些病原体的细胞摄取有关。值得注意的是，癌细胞株已被证明在生长因子刺激下上调巨噬细胞吞噬功能。我们的数据表明，Hssh3bp1的表达增加抑制了巨噬细胞的吞噬作用，并且Hssh3bp1的表达在胶质瘤细胞系中被异常调节。这些数据支持我们的工作假设，即Hssh3bp1通过反对生长因子受体刺激来抑制巨噬细胞吞噬。本研究以人脑胶质瘤细胞系为模型系统，研究Hssh3bp1在巨噬细胞吞噬中的调控机制。Hssh3bp1在巨噬细胞吞噬和细胞生长中的作用可能与其结合伙伴Abl酪氨酸激酶有关。我们对这项研究的机制假设是，酪氨酸磷酸化的Hssh3bp1抑制Abl激酶，导致细胞生长减少，这是因为Abl激酶的多个有丝分裂靶点的磷酸化减少。或者，Hssh3bp1与大胞体中Abl的结合将Abl隔离在细胞质中，因此Abl激酶不能转位到细胞核，这是一个控制细胞生长的过程。除了验证这一假设，我们还将确定是否其他已知的影响巨噬细胞吞噬的蛋白质也调节Hssh3bp1的磷酸化并控制Hssh3bp1的功能。这些研究可能导致在细胞水平上关于巨噬细胞吞噬的分子调控的新信息。

项目成果

Essential role for Abi1 in embryonic survival and WAVE2 complex integrity

• DOI: 10.1073/pnas.1016811108
• 发表时间: 2011-04-26
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Dubielecka, Patrycja M.;Ladwein, Kathrin I.;Kotula, Leszek
• 通讯作者: Kotula, Leszek

Differential regulation of macropinocytosis by Abi1/Hssh3bp1 isoforms.

• DOI: 10.1371/journal.pone.0010430
• 发表时间: 2010-05-10
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Dubielecka PM;Cui P;Xiong X;Hossain S;Heck S;Angelov L;Kotula L
• 通讯作者: Kotula L

Crk and ABI1: binary molecular switches that regulate abl tyrosine kinase and signaling to the cytoskeleton.

• DOI: 10.1177/1947601912460051
• 发表时间: 2012-05-01
• 期刊: Genes & cancer
• 作者: Hossain, Sajjad;Dubielecka, Patrycja M;Kotula, Leszek
• 通讯作者: Kotula, Leszek

Disruption of Abi1/Hssh3bp1 expression induces prostatic intraepithelial neoplasia in the conditional Abi1/Hssh3bp1 KO mice.

Abi1/Hssh3bp1 表达的破坏会在条件性 Abi1/Hssh3bp1 KO 小鼠中诱导前列腺上皮内瘤变。

• DOI: 10.1038/oncsis.2012.28
• 发表时间: 2012
• 期刊: Oncogenesis
• 影响因子: 6.2
• 作者: Xiong,X;Chorzalska,A;Dubielecka,PM;White,JR;Vedvyas,Y;Hedvat,CV;Haimovitz-Friedman,A;Koutcher,JA;Reimand,J;Bader,GD;Sawicki,JA;Kotula,L
• 通讯作者: Kotula,L

Abi1, a critical molecule coordinating actin cytoskeleton reorganization with PI-3 kinase and growth signaling.

• DOI: 10.1016/j.febslet.2012.05.015
• 发表时间: 2012-08-14
• 期刊: FEBS letters
• 影响因子: 3.5
• 作者: Kotula L