Differential cytoskeletal changes during growth cone collapse in response to hSema III and thrombin.
Growth cones are known as the site of action of many factors that influence neurite growth behavior. To assess how different collapsing agents influence the growth cone cytoskeleton, we used recombinant human Semaphorin III (hSema III) and the serine protease thrombin. Embryonic chick dorsal root ganglion neurons showed a dramatic depolymerization of actin filaments within 5 min upon hSema III exposure and virtually no influence on microtubules (MT). Only at later time points (20-30 min) was the polymerization/depolymerization rate of MT significantly affected. Thrombin induced a morphologically and kinetically similar growth cone collapse. Moreover, thrombin induced an early and selective depolymerization of dynamic MT, accompanied by the formation of loops of stable MT bundles. Selective changes in the phosphorylation pattern of tau were associated with microtubule assembly in thrombin-induced responses. Our data provide evidence that different signal transduction pathways lead to distinct changes of the growth cone cytoskeleton.
Fritsche
J
J
Brain Research Institute, University of Zurich, and Swiss Federal Institute of Technology.
Reber
B F
BF
Schindelholz
B
B
Bandtlow
C E
CE
D051339:Actin Depolymerizing Factors; D000199:Actins / Q000032:analysis / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D019556:COS Cells; D002642:Chick Embryo; D003599:Cytoskeleton / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D047630:Depsipeptides; D005455:Fluorescent Antibody Technique; D005727:Ganglia, Spinal / Q000166:cytology; D006023:Glycoproteins / Q000494:pharmacology*; D020439:Growth Cones / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D006490:Hemostatics / Q000494:pharmacology; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism; D009414:Nerve Growth Factors / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000648:ultrastructure; D010456:Peptides, Cyclic / Q000494:pharmacology; D010766:Phosphorylation; D040121:Semaphorin-3A; D013917:Thrombin / Q000494:pharmacology*; D014404:Tubulin / Q000032:analysis / Q000378:metabolism; D014747:Vinblastine / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000737:chemistry / Q000494:pharmacology; D016875:tau Proteins / Q000032:analysis / Q000378:metabolism
D051339:Actin Depolymerizing Factors; D000199:Actins; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D047630:Depsipeptides; D006023:Glycoproteins; D006490:Hemostatics; D008840:Microfilament Proteins; D009414:Nerve Growth Factors; D010456:Peptides, Cyclic; D040121:Semaphorin-3A; D014404:Tubulin; D010566:Virulence Factors, Bordetella; D016875:tau Proteins; C057531:jasplakinolide; D014747:Vinblastine; D013917:Thrombin