Surface remodeling associated with vasopressin-induced membrane traffic in L6 myogenic cells.
The plasma membrane is dynamically remodeled as a function of the cell cycle, motility and membrane traffic. We have previously shown that arg8-vasopressin (AVP) stimulation of L6 myoblasts induces the activation of phosholipase D during the first minutes of stimulation, and the differentiation of 1,6 myoblasts as a long term effect. We now report that AVP also induces two types of morphological responses in L6 cells within a few minutes of stimulation: exocytosis, apparent as uncoated pits, and the generation of membrane projections and reffles. Thus, such an experimental model is suitable for the study of hormone-induced morphological surface modifications and their regulatory mechanisms. In L6 cells, AVP-induced projection generation depends on the integrity of microfilaments, intermediate filaments, and microtubules. Moreover, projection generation and exocytosis appear to be independently regulated phenomena: in fact, inhibition of the de novo synthesis of phosphatidylcholine inhibits membrane traffic but fails to block projection appearance. Conversely, the latter phenomenon, unlike exocytosis, is mediated by PI3-kinase signaling. Thus, AVP induces two early, independently regulated morphological modifications in L6 cells: exocytosis, involved in plasma membrane phospholipid turnover, and membrane projections, likely involved in cell migration.
Coletti
D
D
Department of Histology and Medical Embryology, University La Sapienza, Rome, Italy.
Palleschi
S
S
Silvestroni
L
L
Tomei
F
F
Molinaro
M
M
Adamo
S
S
D000165:Acridine Orange / Q000494:pharmacology; D020106:Acrylamide / Q000494:pharmacology; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects* / Q000648:ultrastructure; D002465:Cell Movement; D003571:Cytochalasin B / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects; D005456:Fluorescent Dyes / Q000494:pharmacology; D005470:Fluorometry; D007700:Kinetics; D008024:Ligands; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009132:Muscles / Q000166:cytology / Q000648:ultrastructure; D017239:Paclitaxel / Q000494:pharmacology; D010713:Phosphatidylcholines / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction; D013997:Time Factors; D014667:Vasopressins / Q000494:pharmacology*; D000077191:Wortmannin
D000730:Androstadienes; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D008024:Ligands; D010713:Phosphatidylcholines; D010743:Phospholipids; D010767:Phosphorylcholine; D014667:Vasopressins; D020106:Acrylamide; D003571:Cytochalasin B; C039128:miltefosine; D019869:Phosphatidylinositol 3-Kinases; D000165:Acridine Orange; D017239:Paclitaxel; D000077191:Wortmannin