Abstract
PC12 cells, like endocrine chromaffin cells, undergo neuronal-like differentiation in response to nerve growth factor (NGF). Here we report that this phenotype conversion produces major changes in release of a green fluorescent protein-tagged neuropeptide-hormone. First, the spatial distribution of the releasable pool is altered; peptide release from untreated cells is supported predominantly by membrane-proximal vesicles, whereas a diffuse pool at the ends of processes is used by NGF-treated cells. Second, the time course of release evoked by photolysis of caged Ca(2+) is faster after differentiation. High-resolution measurements suggest that a slow step before membrane fusion dominates the kinetics of release in untreated cells. Finally, the effect of actin microfilament depolymerization on total release is altered by NGF treatment. This implies that the mechanism that limits the size of the releasable pool is altered by phenotype conversion. Therefore, the cellular organization of peptide release is plastic and changes in response to NGF. This flexibility may be used to generate cell-specific release properties.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Actin Cytoskeleton / metabolism
-
Actins / metabolism
-
Animals
-
Atrial Natriuretic Factor / metabolism
-
Barium / pharmacology
-
Calcium / metabolism
-
Cell Differentiation / drug effects*
-
Chromaffin Cells / cytology
-
Chromaffin Cells / drug effects*
-
Chromaffin Cells / metabolism*
-
Egtazic Acid / analogs & derivatives*
-
Egtazic Acid / metabolism
-
Enzyme Inhibitors / pharmacology
-
Green Fluorescent Proteins
-
Growth Cones / drug effects
-
Growth Cones / metabolism
-
Ionophores / pharmacology
-
Luminescent Proteins
-
Marine Toxins
-
Microscopy, Confocal
-
Nerve Growth Factor / pharmacology*
-
Oxazoles / pharmacology
-
PC12 Cells
-
Peptides / metabolism*
-
Photolysis
-
Protein Precursors / metabolism
-
Rats
-
Recombinant Fusion Proteins / metabolism
-
Secretory Vesicles / metabolism
Substances
-
Actins
-
Enzyme Inhibitors
-
Ionophores
-
Luminescent Proteins
-
Marine Toxins
-
Oxazoles
-
Peptides
-
Protein Precursors
-
Recombinant Fusion Proteins
-
dimethoxynitrophenyl-EGTA-4
-
mycalolide B
-
Green Fluorescent Proteins
-
Barium
-
Egtazic Acid
-
Atrial Natriuretic Factor
-
Nerve Growth Factor
-
Calcium