Structural Insights Uncover the Specific Phosphoinositide Recognition by the PH1 Domain of Arap3.
Int J Mol Sci
; 24(2)2023 Jan 06.
Article
em En
| MEDLINE
| ID: mdl-36674645
ABSTRACT
Arap3, a dual GTPase-activating protein (GAP) for the small GTPases Arf6 and RhoA, plays key roles in regulating a wide range of biological processes, including cancer cell invasion and metastasis. It is known that Arap3 is a PI3K effector that can bind directly to PI(3,4,5)P3, and the PI(3,4,5)P3-mediated plasma membrane recruitment is crucial for its function. However, the molecular mechanism of how the protein recognizes PI(3,4,5)P3 remains unclear. Here, using liposome pull-down and surface plasmon resonance (SPR) analysis, we found that the N-terminal first pleckstrin homology (PH) domain (Arap3-PH1) can interact with PI(3,4,5)P3 and, with lower affinity, with PI(4,5)P2. To understand how Arap3-PH1 and phosphoinositide (PIP) lipids interact, we solved the crystal structure of the Arap3-PH1 in the apo form and complex with diC4-PI(3,4,5)P3. We also characterized the interactions of Arap3-PH1 with diC4-PI(3,4,5)P3 and diC4-PI(4,5)P2 in solution by nuclear magnetic resonance (NMR) spectroscopy. Furthermore, we found overexpression of Arap3 could inhibit breast cancer cell invasion in vitro, and the PIPs-binding ability of the PH1 domain is essential for this function.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfatidilinositóis
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Proteínas Ativadoras de GTPase
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Proteínas Adaptadoras de Transdução de Sinal
Limite:
Humans
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article