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Printable Handouts
Navigable Slide Index
- Introduction
- Overview: O-GlcNAc or O-GlcNAcylation
- More than 3000 proteins are O-GlcNAc modified
- O-GlcNAc was discovered serendipitously
- Why was O-GlcNAc only discovered in 1984?>
- Overview: biosynthesis of O-GlcNAc
- The biosynthesis of O-GlcNAc
- The O-GlcNAc Transferase (OGT) (1)
- The O-GlcNAc Transferase (OGT) (2)
- Structure of the O-GlcNAc transferase
- OGT regulation: UDP-GlcNAc concentrations
- OGT regulation: substrate-protein interactions
- OGT regulation: protein -protein interactions
- OGT regulation: post-translational modifications
- O-GlcNAcase removes O-GlcNAc
- O-GlcNAc regulation of proteins at molecular level
- What is the role of O-GlcNAcylation
- Regulation of protein phosphorylation
- O-GlcNAc itself may be phosphorylated at C6
- Regulation of enzyme activity
- Protein turnover
- Protein solubility
- The cellular functions of O-GlcNAc modification
- O-GlcNAc is involved in many cellular processes
- O-GlcNAc, epigenetics and transcription
- O-GlcNAc and translation
- O-GlcNAc and the cell cycle
- O-GlcNAc and nutritional sensing
- O-GlcNAc respond to extracellular glucose levels
- More about O-GlcNAc and nutritional signaling
- O-GlcNAc & neurodegenerative diseases
- O-GlcNAc and Amyloid-b levels in Alzheimer's
- Glycosylation suppresses g-Secretase activity
- O-GlcNAc and Cancer
- O-GlcNAc as a regulator of stress response
- O-GlcNAc stress response is highly conserved
- Mechanisms of O-GlcNAcylation during stress
- O-GlcNAcylation: a protective response of cells
- O-GlcNAcylation: a protective response of tissues
- O-GlcNAc-protective in trauma hemorrhage models
- Further effects of O-GlcNAc mediated protection
- O-GlcNAc regulates the expression of HSPs
- Proteins O-GlcNAc-modifies in stress & injury
- Summary: stress
- Overall summary
- Citations
Topics Covered
- O-GlcNAc
- A Novel Intracellular Glycan
- Biosynthesis of O-GlcNAc
- Mechanisms by which O-GlcNAc regulates proteins
- Cellular pathways and diseases regulated by O-GlcNAc
- Epigenetics and transcription
- Translation
- Cell cycle
- Nutritional sensing
- Neurodegeneration
- Cancer
- The cellular stress response
Talk Citation
Zachara, N. (2014, March 13). O-GlcNAc, an essential regulator of numerous cellular pathways [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved April 15, 2025, from https://doi.org/10.69645/FAHS9315.Export Citation (RIS)
Publication History
- Published on March 13, 2014
Financial Disclosures
- Dr. Natasha Zachara has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
A selection of talks on Cell Biology
Transcript
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0:00
Welcome to
this lecture for Henry Stewart
Talks in which we will discuss
the O-GIcNAc modification
and its essential regulatory role
in numerous cellular pathways.
My name is Natasha Zachara and
I'm a member of the Department
of Biological Chemistry at the
Johns Hopkins University School
of Medicine.
0:21
We will start by defining, what
is O-GIcNAc or O-GIcNAcylation?
The O-GIcNAc modification or
O-GIcNAcylation is the modification
of nuclear, cytoplasmic,
and mitochondrial protein
by monosaccharides of O-linked
beta-N-acetyl-D-glucosamine.
O-GIcNAc is added and removed
dynamically by just two enzymes,
the O-GIcNAc transferase,
shortened to OGT,
catalyzes the addition of O-GIcNAc.
And O-GIcNAc is removed by
neutral N-acetylglucasaminidase,
known as O-GIcNAcase.
O-GIcNAc is common in
metazoans, but there is also
evidence for this modification in
Aspergilus, protozoa, and Listeria.
O-GIcNAc has long been
considered a novel form
a protein glycosylation
for three reasons.
Firstly, its localization.
Unlike prototypical glycosylation,
which is added in the ER and Golgi,
the addition and removal of O-GIcNAc
is catalyzed in the nucleus,
the cytoplasm, and the mitochondria.
And, in fact, the protein modified
by O-GIcNAc exist in the same loci
rather than in the
endomembrane system.
The addition and removal of
O-GIcNAc is very dynamic.
Thus, the sugar is added
and removed to proteins
many times during their lifetime.
And, finally, with the exception
of nuclear pore proteins,
O-GIcNAc is not further modified
into more complex glycan
structures.