Structural Basis for Phosphatidylinositol Phosphate Kinase Type Iγ Binding to Talin at Focal Adhesions

Pereda, José M. de; Wegener, Kate L.; Santelli, Eugenio; Bate, Neil; Ginsberg, Mark H.; Critchley, David R.; Campbell, Iain D.; Liddington, Robert

doi:10.1074/jbc.m413180200

Cited by 70 publications

(100 citation statements)

References 31 publications

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“…8D), which is in accord with the mapped talin binding region (see Fig. 6A) (38,51,62) and structural studies of the talin FERM F3 subdomain engaged with PIPKI␥ peptide (63,64). Altogether these data indicate that aromatic residues contribute to ␤2 sandwich subdomain binding possibly through inserting into complementary hydrophobic surfaces in the appendage.…”

Section: Pipki␥661 Membrane Translocation and Ap-2 Recruitment-synaptsupporting

confidence: 67%

Clathrin Regulates the Association of PIPKIγ661 with the AP-2 Adaptor β2 Appendage

Thieman

Mishra

Ling

et al. 2009

Journal of Biological Chemistry

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The AP-2 clathrin adaptor differs fundamentally from the related AP-1, AP-3, and AP-4 sorting complexes because membrane deposition does not depend directly on an Arf family GTPase. Instead phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P 2 ) appears to act as the principal compartmental cue for AP-2 placement at the plasma membrane as well as for the docking of numerous other important clathrin coat components at the nascent bud site. This PtdIns(4,5)P 2 dependence makes type I phosphatidylinositol 4-phosphate 5-kinases (PIPKIs) lynchpin enzymes in the assembly of clathrin-coated structures at the cell surface. PIPKI␥ is the chief 5-kinase at nerve terminals, and here we show that the 26-amino acid, alternatively spliced C terminus of PIPKI␥661 is an intrinsically unstructured polypeptide that binds directly to the sandwich subdomain of the AP-2 ␤2 subunit appendage. An aromatic side chain-based, extended interaction motif that also includes the two bulky C-terminal residues of the short PIPKI␥635 variant is necessary for ␤2 appendage engagement. The clathrin heavy chain accesses the same contact surface on the AP-2 ␤2 appendage, but because of additional clathrin binding sites located within the unstructured hinge segment of the ␤2 subunit, clathrin binds the ␤2 chain with a higher apparent affinity than PIPKI␥661. A clathrin-regulated interaction with AP-2 could allow PIPKI␥661 to be strategically positioned for regional PtdIns(4,5)P 2 generation during clathrin-coated vesicle assembly at the synapse.The key regulatory activity of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P 2 ) 2 during clathrin-mediated endocytosis is firmly established (1, 2). The heterotetrameric AP-2 adaptor complex and numerous clathrin-associated sorting proteins (CLASPs) display dedicated surfaces or domains that engage PtdIns(4,5)P 2 with good selectively (3-5). PtdIns(4,5)P 2 , which is localized to the cell surface, thus biases the deposition and assembly of these coat components at the plasma membrane by synergizing with other low affinity interactions in a phenomenon termed coincidence detection (2, 4). Later acting endocytic regulatory proteins also bind to PtdIns(4,5)P 2 . The large GTPase dynamin contains a pleckstrin homology domain, which engages PtdIns(4,5)P 2 and is required for vesicle scission (6). Similarly the clathrin uncoating cofactor, auxilin, has a PTEN homology domain that also binds to phosphoinositides and is necessary for targeting of this J-domain protein to clathrin-coated membranes (7). The lipid binding features of all these endocytic components is in full accord with PtdIns(4,5)P 2 being necessary for both early and late stages of coated vesicle production (8).PtdIns(4,5)P 2 is a general, apparently ubiquitous marker of the plasma membrane, and the concept of functionally autonomous, stable PtdIns(4,5)P 2 -enriched microdomains within the cytosolic leaflet of the membrane has been challenged (9 -11). This raises the question of whether the prevailing PtdIns(4,5)P 2 concentration at the cell surf...

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Section: Pipki␥661 Membrane Translocation and Ap-2 Recruitment-synaptsupporting

confidence: 67%

Clathrin Regulates the Association of PIPKIγ661 with the AP-2 Adaptor β2 Appendage

Thieman

Mishra

Ling

et al. 2009

Journal of Biological Chemistry

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“…4B). The resulting change in FP was fit to an isotherm with a K d of 160 M AE 50 M, consistent with reported affinities of 170 nM to 1.4 μM for other PIP5KIγ constructs with slightly different sequences (36,37).…”

Section: Resultsmentioning

confidence: 99%

Affinity of talin-1 for the β3-integrin cytosolic domain is modulated by its phospholipid bilayer environment

Moore

Nygren

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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Binding of the talin-1 FERM (4.1/ezrin/radixin/moesin) domain to the β3 cytosolic tail causes activation of the integrin αIIbβ3. The FERM domain also binds to acidic phospholipids. Although much is known about the interaction of talin-1 with integrins and lipids, the relative contribution of each interaction to integrin regulation and possible synergy between them remain to be clarified. Here, we examined the thermodynamic interplay between FERM domain binding to phospholipid bilayers and to its binding sites in the β3 tail. We found that although both the F0F1 and F2F3 subdomains of the talin-1 FERM domain bind acidic bilayers, the full-length FERM domain binds with an affinity similar to F2F3, indicating that F0F1 contributes little to the overall interaction. When free in solution, the β3 tail has weak affinity for the FERM domain. However, appending the tail to acidic phospholipids increased its affinity for the FERM domain by three orders of magnitude. Nonetheless, the affinity of the FERM for the appended tail was similar to its affinity for binding to bilayers alone. Thus, talin-1 binding to the β3 tail is a ternary interaction dominated by a favorable surface interaction with phospholipid bilayers and set by lipid composition. Nonetheless, interactions between the FERM domain, the β3 tail, and lipid bilayers are not optimized for a high-affinity synergistic interaction, even at the membrane surface. Instead, the interactions appear to be tuned in such a way that the equilibrium between inactive and active integrin conformations can be readily regulated.cytoskeleton | plasma membrane | platelet aggregation T he integrin αIIbβ3 resides on the platelet surface in equilibrium between resting and active conformations (1-5). On circulating platelets, αIIbβ3 is constrained in its inactive conformation to prevent spontaneous platelet aggregation. Similarly, the cytoskeletal protein talin-1, whose binding to the β3 cytosolic tail (CT) stabilizes the active conformation of αIIbβ3 (6-8), is sequestered away from the β3 CT (9). Besides interacting with integrins, talin-1 interacts with negatively charged phospholipids (10-12) and phosphoinositides (13)(14)(15)(16). Stimuli generated at sites of vascular damage recruit talin-1 to the platelet plasma membrane, thereby promoting αIIbβ3 activation (17-19). Much is known about the interaction of talin-1 with integrins and lipids, but the relative contribution of each interaction to integrin regulation and possible synergy between them remain to be clarified. Elucidating these interactions is important for understanding events leading to and controlling the formation of integrin complexes and for potential pharmacologic modulation of integrin signaling.Talin-1 is a 250-kD protein containing a 45-kD N-terminal head domain attached via a flexible linker to a 200-kD C-terminal rod domain (7). Because the head domain is packed against the rod domain in its inactive state (20), talin-1 recruitment to the membrane and to integrin β CTs requires disruption of this interaction (1...

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“…Src-induced phosphorylation of the NPxY motif dissociates ligand-bound integrin β-tails from the talin F3 lobe [94]. The released talin head may recruit and activate phosphatidylinositol (4) phosphate 5 kinase type Iγ(PIPKIγ) [95][96][97], generating PIP2 which coactivate a number of focal adhesion proteins, including vinculin and talin. The released liganded integrins may further activate Syk in focal complexes, or bind tensin, converting focal-into fibrillar adhesions.…”

Section: Outside-in Signalingmentioning

confidence: 99%

Structure and mechanics of integrin-based cell adhesion

Arnaout

Xiong

2007

Current Opinion in Cell Biology

374

284

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Summary of Recent AdvancesIntegrins are α/β heterodimeric adhesion glycoprotein receptors that regulate a wide variety of dynamic cellular processes such as cell migration, phagocytosis and growth and development. X-ray crystallography of the integrin ectodomain revealed its modular architecture and defined its metaldependent interaction with extracellular ligands. This interaction is regulated from inside the cell (inside-out activation), through the short cytoplasmic α and β integrin tails, which also mediate biochemical and mechanical signals transmitted to the cytoskeleton by the ligand-occupied integrins, which effect major changes in cell shape, behavior and fate. Recent advances in the structural elucidation of integrins and integrin binding cytoskeleton proteins are the subject of this review.

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Structural Basis for Phosphatidylinositol Phosphate Kinase Type Iγ Binding to Talin at Focal Adhesions

Cited by 70 publications

References 31 publications

Clathrin Regulates the Association of PIPKIγ661 with the AP-2 Adaptor β2 Appendage

Clathrin Regulates the Association of PIPKIγ661 with the AP-2 Adaptor β2 Appendage

Affinity of talin-1 for the β3-integrin cytosolic domain is modulated by its phospholipid bilayer environment

Structure and mechanics of integrin-based cell adhesion

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