SRD5A3

SRD5A3

The SRD5A3 gene encodes the enzyme steroid 5-alpha-reductase 3, which is involved in the conversion of polyprenol to dolichol, a critical step in the synthesis of glycoproteins. This enzyme is part of the steroid 5-alpha-reductase family, which also includes enzymes involved in the metabolism of steroids.

Function

SRD5A3 is primarily responsible for the conversion of polyprenol to dolichol, a process essential for the proper synthesis of N-linked glycoproteins. Dolichol is a lipid that plays a crucial role in the glycosylation of proteins, a post-translational modification that is vital for protein folding, stability, and function.

The enzyme encoded by SRD5A3 is a polyprenol reductase, which catalyzes the reduction of the alpha-isoprene unit of polyprenols to form dolichols. This reaction is a key step in the dolichol biosynthesis pathway, which is necessary for the assembly of the oligosaccharide precursor used in N-glycosylation.

Clinical Significance

Mutations in the SRD5A3 gene have been associated with a rare congenital disorder known as SRD5A3-congenital disorder of glycosylation (SRD5A3-CDG). This disorder is characterized by a wide range of symptoms, including developmental delay, intellectual disability, and various physical abnormalities. The condition arises due to defects in glycoprotein biosynthesis, leading to improper glycosylation of proteins.

Patients with SRD5A3-CDG often present with neurological symptoms, ocular abnormalities, and skin manifestations. The diagnosis is typically confirmed through genetic testing, which reveals mutations in the SRD5A3 gene.

Genetic Information

The SRD5A3 gene is located on chromosome 4q12. It consists of several exons and encodes a protein that is approximately 318 amino acids in length. The gene is expressed in various tissues, with higher expression levels observed in the liver and other organs involved in glycoprotein synthesis.

Research and Developments

Research into SRD5A3 and its associated disorders is ongoing, with studies focusing on understanding the molecular mechanisms underlying the enzyme's function and the pathogenesis of SRD5A3-CDG. Efforts are also being made to develop potential therapeutic strategies to manage or treat the symptoms associated with this disorder.

Also see

• Glycosylation
• Congenital disorder of glycosylation
• Steroid 5-alpha-reductase
• Dolichol