Facilitative glucose transporter Glut1 is actively excluded from rod outer segments.
Abstract
Photoreceptors are among the most metabolically active cells in the body, relying
on both oxidative phosphorylation and glycolysis to satisfy their high energy needs.
Local glycolysis is thought to be particularly crucial in supporting the function
of the photoreceptor's light-sensitive outer segment compartment, which is devoid
of mitochondria. Accordingly, it has been commonly accepted that the facilitative
glucose transporter Glut1 responsible for glucose entry into photoreceptors is localized
in part to the outer segment plasma membrane. However, we now demonstrate that Glut1
is entirely absent from the rod outer segment and is actively excluded from this compartment
by targeting information present in its cytosolic C-terminal tail. Our data indicate
that glucose metabolized in the outer segment must first enter through other parts
of the photoreceptor cell. Consequently, the entire energy supply of the outer segment
is dependent on diffusion of energy-rich substrates through the thin connecting cilium
that links this compartment to the rest of the cell.
Type
Journal articleSubject
AnimalsAnimals, Genetically Modified
Facilitated Diffusion
Glucose
Glucose Transporter Type 1
Mice
Mice, Inbred Strains
Mutagenesis, Site-Directed
Photoreceptor Connecting Cilium
Protein Engineering
Protein Sorting Signals
Protein Transport
Rats
Retinal Photoreceptor Cell Inner Segment
Rod Cell Outer Segment
Sequence Deletion
Transgenes
Xenopus laevis
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https://hdl.handle.net/10161/4190Published Version (Please cite this version)
10.1242/jcs.072389Publication Info
Gospe, Sidney M; Baker, Sheila A; & Arshavsky, Vadim Y (2010). Facilitative glucose transporter Glut1 is actively excluded from rod outer segments.
J Cell Sci, 123(Pt 21). pp. 3639-3644. 10.1242/jcs.072389. Retrieved from https://hdl.handle.net/10161/4190.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Vadim Y Arshavsky
Helena Rubinstein Foundation Distinguished Professor of Ophthalmology
Research conducted in our laboratory is dedicated to understanding how vision is performed
on the molecular level. Our most mature direction addresses the function of rod and
cone photoreceptors, which are sensory neurons responsible for the detection and primary
processing of information entering the eye in the form of photons. Photoreceptors
respond to capturing photons by generating electrical signals transmitted to the secondary
neurons in the retina and, ultimately, to the brain. Our wor
Sidney Maloch Gospe III
Assistant Professor of Ophthalmology
Dr. Gospe joined Duke Ophthalmology on August 1, 2017 following his neuro-ophthalmology
fellowship training at Duke. His research interests center on developing novel genetic
mouse models of severe mitochondrial dysfunction in retinal ganglion cells (RGCs)
and other retinal neurons in order to recapitulate the RGC degeneration seen in human
optic neuropathies and the poorly understood pigmentary retinopathy that may accompany
these diseases.
Mitochondria are the powerhouse o
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