Related Experiment Video
Updated: Jun 10, 2026
11:25
Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
Published on: October 4, 2017
SRD5A3: A surprising role in glycosylation
Ashlee R Stiles1, David W Russell
1Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA.
Cell
|July 27, 2010
Summary
The steroid 5alpha-reductase (SRD5A) enzyme family is vital for male sexual development. A study reveals SRD5A3
Area of Science:
- Biochemistry
- Genetics
- Endocrinology
Background:
- The steroid 5alpha-reductase (SRD5A) enzyme family plays a key role in synthesizing steroid hormones essential for male sexual development.
- Previous research focused on SRD5A's role in hormone production.
Discussion:
- Cantagrel et al. (2010) identified SRD5A3 as a polyprenol reductase, expanding its known functions beyond steroid hormone synthesis.
- This finding highlights SRD5A3's critical involvement in the N-linked protein glycosylation pathway.
Key Insights:
- SRD5A3 functions as a polyprenol reductase, a previously unrecognized role for this enzyme family member.
- Mutations in SRD5A3 are identified as the causative agent for a rare Mendelian disorder, linking enzymatic function to human disease.
- The study establishes a direct link between SRD5A3, polyprenol reduction, N-linked glycosylation, and a specific genetic disorder.
Outlook:
- Further research into SRD5A3's precise mechanism in glycosylation could reveal new therapeutic targets.
- Understanding the spectrum of SRD5A3-related disorders may improve diagnosis and patient management.
- Investigating other SRD5A family members for similar non-hormonal roles could uncover broader biological significance.
Related Concept Videos
01:25Protein Glycosylation
Glycosylation, the most common post-translational modification for proteins, serves diverse functions. Adding sugars to proteins makes the proteins more resistant to proteolytic digestion. Glycosylated proteins can act as markers and receptors to promote cell-cell adhesion. Additionally, they have many essential quality control functions in the cell, such as correct protein folding and facilitating transport of misfolded proteins to the cytosol, which can be degraded.
Glycosylation occurs in...
Glycosylation occurs in...
01:24Oligosaccharide Assembly
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
01:29Protein Folding Quality Check in the RER
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
01:26Protein Modifications in the RER
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
01:05Proteoglycans
Glycans, a class of complex heterogeneous molecules, can be covalently attached to proteins to form glycosylated proteins that regulate various physiological and pathological processes. Glycosylated proteins or glycoproteins comprise N-linked and O-linked oligosaccharides. O-glycosylation is the most common type of protein glycosylation. Here, glycans attach to the oxygen atom of the hydroxyl groups of Serine or Threonine residues. O-linked glycosylation occurs later in protein processing,...
01:23Glycosaminoglycans
Glycosaminoglycans (GAGs), also known as mucopolysaccharides, are long and linear polymers comprising of specific repeating disaccharides - the amino sugar that can be N-acetylglucosamine or N-acetylgalactosamine, and a uronic acid that is usually glucuronic acid or iduronic acid.
GAGS are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Due to their polar nature they attract water, and serve as excellent lubricants or shock absorbers in an animal body.
Hyaluronic...
GAGS are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Due to their polar nature they attract water, and serve as excellent lubricants or shock absorbers in an animal body.
Hyaluronic...