Formation of signal transduction complexes during immobile phase of NGFR movements.
Nerve growth factor (NGF) is a secreted neurotrophin involved in the differentiation, growth, and maintenance of neurons. Here, we have used single-molecule imaging to characterize the behavior of Cy3-tagged NGF after binding to receptor complexes on the surfaces of PC12 cells. We show that NGF-receptor complexes have two distinct diffusive states, characterized as mobile and immobile phase. The transition between the two diffusive states occurred reversibly with duration times determined by a single rate limiting process. The abrupt transition to the immobile phase often occurred simultaneously with the clustering of NGF-receptor complexes. Immobilization depended on the phosphorylation of the TrkA NGF-receptor. Using dual-color imaging, it was demonstrated that the membrane recruitment of the intercellular signaling protein occurs with NGF-receptor complexes in the immobile phase indicating signal transduction occurs during this phase. Thus, NGF signaling is performed through a repetitive random process to induce transient formation of signaling complexes.
Department of Anesthesiology, Graduate School of Medicine, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.
Sho C
SC
Shibata
Kayo
K
Hibino
Takashi
T
Mashimo
Toshio
T
Yanagida
Yasushi
Y
Sako
D000818:Animals; D009068:Movement; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D016716:PC12 Cells; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D051381:Rats; D020800:Receptor, Nerve Growth Factor / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction
D046912:Multiprotein Complexes; D047428:Protein Kinase Inhibitors; D020800:Receptor, Nerve Growth Factor; D019908:Proto-Oncogene Proteins c-raf