Dynamic recruitment of phospholipase C gamma at transiently immobilized GPI-anchored receptor clusters induces IP3-Ca2+ signaling: single-molecule tracking study 2.
Clusters of CD59, a glycosylphosphatidylinositol-anchored receptor (GPI-AR), with physiological sizes of approximately six CD59 molecules, recruit Galphai2 and Lyn via protein-protein and raft interactions. Lyn is activated probably by the Galphai2 binding in the same CD59 cluster, inducing the CD59 cluster's binding to F-actin, resulting in its immobilization, termed stimulation-induced temporary arrest of lateral diffusion (STALL; with a 0.57-s lifetime, occurring approximately every 2 s). Simultaneous single-molecule tracking of GFP-PLCgamma2 and CD59 clusters revealed that PLCgamma2 molecules are transiently (median = 0.25 s) recruited from the cytoplasm exclusively at the CD59 clusters undergoing STALL, producing the IP(3)-Ca(2+) signal. Therefore, we propose that the CD59 cluster in STALL may be a key, albeit transient, platform for transducing the extracellular GPI-AR signal to the intracellular IP(3)-Ca(2+) signal, via PLCgamma2 recruitment. The prolonged, analogue, bulk IP(3)-Ca(2+) signal, which lasts for more than several minutes, is likely generated by the sum of the short-lived, digital-like IP(3) bursts, each created by the transient recruitment of PLCgamma2 molecules to STALLed CD59.
Suzuki
Kenichi G N
KG
Membrane Mechanisms Project, International Cooperative Research Project, Japan Science and Technology Agency, The Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan.
Fujiwara
Takahiro K
TK
Edidin
Michael
M
Kusumi
Akihiro
A
D000818:Animals; D018957:CD59 Antigens / Q000502:physiology; D020013:Calcium Signaling / Q000502:physiology*; D002460:Cell Line; D017261:Glycosylphosphatidylinositols / Q000502:physiology*; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology*; D008856:Microscopy, Fluorescence; D051966:Phospholipase C gamma / Q000378:metabolism*; D048328:Potoroidae; D051381:Rats; D011956:Receptors, Cell Surface / Q000502:physiology*
D018957:CD59 Antigens; D017261:Glycosylphosphatidylinositols; D011956:Receptors, Cell Surface; D015544:Inositol 1,4,5-Trisphosphate; D051966:Phospholipase C gamma