Abstract
Cyclic adenosine 3':5'-monophosphate (cAMP)-binding proteins and cAMP-dependent protein phosphorylation were examined in growth cone particles (GCPs) prepared from fetal rat brain. Several major proteins which specifically bind a photoactivatable analogue of cAMP are observed in GCPs and correspond to isoelectric variants of the regulatory subunits of the cAMP-dependent protein kinase described in adult brain. We found no evidence for differential compartmentalization of specific cAMP-binding proteins in subcellular fractions of fetal brain or within GCPs. cAMP-stimulated phosphoproteins of GCPs are similar to cAMP-dependent protein kinase substrates characterized in nerve terminals (synaptosomes) of adult brain and include the nerve terminal-specific protein, synapsin I. However, as shown in the companion paper (Katz, F., L. Ellis, and K. H. Pfenninger (1985) J. Neurosci. 5: 1402-1411), this synaptic phosphoprotein is not the major kinase substrate in the GCP fraction. The finding of synapsin I in a subcellular fraction prepared from fetal brain suggests that components of the mature nerve terminal are already present in fetal brain during neuronal sprouting and prior to synaptogenesis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
