A role for talin in presynaptic function.
Talin, an adaptor between integrin and the actin cytoskeleton at sites of cell adhesion, was recently found to be present at neuronal synapses, where its function remains unknown. Talin interacts with phosphatidylinositol-(4)-phosphate 5-kinase type Igamma, the major phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P(2)]-synthesizing enzyme in brain. To gain insight into the synaptic role of talin, we microinjected into the large lamprey axons reagents that compete the talin-PIP kinase interaction and then examined their effects on synaptic structure. A dramatic decrease of synaptic actin and an impairment of clathrin-mediated synaptic vesicle endocytosis were observed. The endocytic defect included an accumulation of clathrin-coated pits with wide necks, as previously observed after perturbing actin at these synapses. Thus, the interaction of PIP kinase with talin in presynaptic compartments provides a mechanism to coordinate PI(4,5)P(2) synthesis, actin dynamics, and endocytosis, and further supports a functional link between actin and clathrin-mediated endocytosis.
Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06519, USA.
Jennifer R
JR
Morgan
Gilbert
G
Di Paolo
Hauke
H
Werner
Valentina A
VA
Shchedrina
Marc
M
Pypaert
Vincent A
VA
Pieribone
Pietro
P
De Camilli
D000199:Actins / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion; D002966:Clathrin / Q000378:metabolism; D004705:Endocytosis; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D007798:Lampreys; D050356:Lipid Metabolism; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000737:chemistry; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D013569:Synapses / Q000378:metabolism* / Q000502:physiology*; D016608:Talin / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors
D000199:Actins; D002966:Clathrin; D010455:Peptides; D016608:Talin; D005982:Glutathione Transferase; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase