Multiple neuropeptides derived from a common precursor are differentially packaged and transported.
The ELH prohormone is proteolytically processed into at least nine peptides which govern egg-laying behavior in Aplysia. Quantitative immunocytochemistry demonstrates that peptides derived from the prohormone are packaged into distinct vesicle classes. Further experiments suggest the segregation occurs via a rapid initial proteolytic cleavage of the prohormone followed by sorting at the trans Golgi. Egg-laying hormone (ELH) immunoreactivity is localized to the cell body and processes, while bag cell peptide (BCP) immunoreactivity is greater in the cell body. Steady state levels of the amino-terminal set of peptides including the BCPs are 3- to 8-fold lower than the carboxy-terminal cleavage products, such as ELH. Thus, intracellular packaging and routing of the peptides cleaved from a single prohormone regulate their localization and levels in these neurons.
Fisher
J M
JM
Department of Biological Sciences, Stanford University, California 94305.
Sossin
W
W
Newcomb
R
R
Scheller
R H
RH
D000818:Animals; D001048:Aplysia / Q000502:physiology*; D001692:Biological Transport; D002451:Cell Compartmentation; D003594:Cytoplasmic Granules / Q000378:metabolism; D007150:Immunohistochemistry; D007447:Invertebrate Hormones / Q000378:metabolism*; D008854:Microscopy, Electron; D009474:Neurons / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational
D007447:Invertebrate Hormones; D011498:Protein Precursors; C026880:egg-laying hormone, Mollusca