TRANSPORT AND SORTING OF NEURONAL MEMBRANE PROTEINS

Project: Research project

Description

Neurons synthesize, sort, and transport numerous membrane proteins
for localization to highly specialized functional domains on their
plasma membranes. The molecular mechanisms whereby they accomplish
this targeting are unknown. The long range-goal of this project
is to determine the molecular signal(s) responsible for targeting
neuronal membrane proteins to their appropriate destinations on the
cell surface and the mechanism whereby they are retained within
selected regions of the plasma membrane. As a first step in
understanding these mechanisms we have chosen to study the
processing, transport, and localization of acetylcholinesterase
(AChE) in tissue-cultured CNS neurons. AChE is the enzyme that
hydrolyses the acetylcholine released by cholinergic nerves. This
enzyme exists as a complex family of oligomeric forms, a subset of
which are rapidly transported down the axon. In addition, a single
integral membrane form of AChE is targeted to the surface plasma
membrane in tissue cultured neurons where it is localized in
clusters along the neurites. It is likely that the mechanism(s)
employed by neurons to sort and transport AChE molecules will be
shared by most if not all rapidly transported neuronal membrane
proteins, whereas the final targeting will depend upon specific
characteristics of subsets of membrane proteins. These are basic
studies that will lead to an understanding of how all nerve cells
sort and transport membrane proteins to specific regions of their
plasma membranes. Our specific aims during the tenure of this proposal are: 1) to
determine where, when, and how the signal specifying membrane
localization of AChE in CNS neurons occurs; 2) to clone and
identify full length cDNAs encoding the AChE polypeptides from
chicken CNS neurons using a full length Torpedo AChE cDNA as a
probe, 3) to express these cDNAs in mouse L cells to study the fate
of the chicken AChE polypeptides, and 4) to inject synthesized
AChE, VSV G-glycoprotein, and IL2 receptor mRNA into identified
neurons of the leech (Hirudo medicinalis) to study the transport
and localization of an identified rapidly transported protein and
foreign membrane proteins in vivo.
StatusFinished
Effective start/end date2/1/881/31/92

Funding

  • National Institutes of Health: $90,055.00
  • National Institutes of Health
  • National Institutes of Health

Fingerprint

Acetylcholinesterase
Membrane Proteins
Neurons
Membranes
Complementary DNA
Hirudo medicinalis
Torpedo
Leeches
Peptides
Membrane Transport Proteins
Interleukin-2 Receptors
Neurites
Cholinergic Agents
Acetylcholine
Axons
Chickens
Glycoproteins
Clone Cells
Cell Membrane
Messenger RNA

ASJC

  • Medicine(all)
  • Neuroscience(all)