3H1Z

Molecular basis for the association of PIPKIgamma -p90 with the clathrin adaptor AP-2

Summary for 3H1Z

• Entry DOI: 10.2210/pdb3h1z/pdb
• Descriptor: AP-2 complex subunit beta-1, Phosphatidylinositol-4-phosphate 5-kinase type-1 gamma (3 entities in total)
• Functional Keywords: phosphatidylinositol 4, 5-bisphosphate, clathrin, adaptor complex ap-2, endocytosis, alternative splicing, cell membrane, coated pit, membrane, phosphoprotein, disease mutation, kinase, transferase
• Biological source: Rattus norvegicus (Rat); More
• Cellular location: Cell membrane : P62944; Cell membrane; Peripheral membrane protein; Cytoplasmic side. Isoform 2: Cytoplasm: O60331
• Total number of polymer chains: 2
• Total formula weight: 31145.67

Authors

Vahedi-Faridi, A.,Kahlfeldt, N.,Schaefer, J.G.,Krainer, G.,Keller, S.,Saenger, W.,Krauss, M.,Haucke, V. (deposition date: 2009-04-14, release date: 2009-11-24, Last modification date: 2023-11-01)

Primary citation

Kahlfeldt, N.,Vahedi-Faridi, A.,Koo, S.J.,Schafer, J.G.,Krainer, G.,Keller, S.,Saenger, W.,Krauss, M.,Haucke, V.
Molecular basis for association of PIPKI gamma-p90 with clathrin adaptor AP-2.
J.Biol.Chem., 285:2734-2749, 2010

PubMed Abstract: Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) is an essential determinant in clathrin-mediated endocytosis (CME). In mammals three type I phosphatidylinositol-4-phosphate 5-kinase (PIPK) enzymes are expressed, with the I gamma-p90 isoform being highly expressed in the brain where it regulates synaptic vesicle (SV) exo-/endocytosis at nerve terminals. How precisely PI(4,5)P(2) metabolism is controlled spatially and temporally is still uncertain, but recent data indicate that direct interactions between type I PIPK and components of the endocytic machinery, in particular the AP-2 adaptor complex, are involved. Here we demonstrated that PIPKI gamma-p90 associates with both the mu and beta2 subunits of AP-2 via multiple sites. Crystallographic data show that a peptide derived from the splice insert of the human PIPKI gamma-p90 tail binds to a cognate recognition site on the sandwich subdomain of the beta2 appendage. Partly overlapping aromatic and hydrophobic residues within the same peptide also can engage the C-terminal sorting signal binding domain of AP-2mu, thereby potentially competing with the sorting of conventional YXXØ motif-containing cargo. Biochemical and structure-based mutagenesis analysis revealed that association of the tail domain of PIPKI gamma-p90 with AP-2 involves both of these sites. Accordingly the ability of overexpressed PIPKI gamma tail to impair endocytosis of SVs in primary neurons largely depends on its association with AP-2 beta and AP-2mu. Our data also suggest that interactions between AP-2 and the tail domain of PIPKI gamma-p90 may serve to regulate complex formation and enzymatic activity. We postulate a model according to which multiple interactions between PIPKI gamma-p90 and AP-2 lead to spatiotemporally controlled PI(4,5)P(2) synthesis during clathrin-mediated SV endocytosis.

PubMed: 19903820
DOI: 10.1074/jbc.M109.074906

Experimental method

X-RAY DIFFRACTION (1.83 Å)