Inhibition of PACAP activity by a receptor antagonist results in changes in cell cycle and apoptotic proteins in chick neuroblasts.
We showed previously that early chick neuroblasts stop proliferating and undergo apoptosis when deprived of endogenous pituitary adenylate cyclase-activating polypeptide (PACAP). To identify proteins involved in these processes, we blocked the primary PACAP receptor and determined protein changes using isotope-coded affinity tag (ICAT) analysis. Cell cycle exit was characterized by a decrease in proteins regulating ribosome biogenesis and protein translation. Apoptosis was linked directly to a tumor suppressor that increases apoptosome activity and indirectly to reduced mitochondrial activity. ICAT analysis, combined with flow cytometric analysis, suggested that some cells were differentiating, rather than undergoing apoptosis. In summary, we have confirmed that withdrawal of PACAP from early chick neuroblasts causes cell cycle exit and apoptosis, and identified proteins involved in proliferation, exit, apoptosis, and possibly differentiation.
Erhardt
Nola M
NM
Department of Biology, University of Victoria, Victoria, British Columbia, Canada.
Haines
Lee R
LR
Pearson
Terry W
TW
Sherwood
Nancy M
NM
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D002642:Chick Embryo; D003513:Cycloheximide / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D007553:Isotope Labeling; D024101:Mitochondrial Proteins / Q000378:metabolism; D009414:Nerve Growth Factors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009479:Neuropeptides / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011500:Protein Synthesis Inhibitors / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D019311:Staurosporine / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism
D004791:Enzyme Inhibitors; D024101:Mitochondrial Proteins; D009414:Nerve Growth Factors; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011500:Protein Synthesis Inhibitors; D011956:Receptors, Cell Surface; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D025521:Tumor Suppressor Proteins; D003513:Cycloheximide; D019311:Staurosporine