GNAS complex locus

GNAS complex locus is a gene that provides instructions for making a protein known as the Gs alpha subunit. This protein plays a crucial role in many cell functions by stimulating activity of an enzyme called adenylate cyclase. The GNAS complex locus is an example of an imprinted gene, which means that only one of the two copies of the gene is active, or "expressed." The active copy determines the specific features of certain rare disorders such as Albright hereditary osteodystrophy and pseudohypoparathyroidism.

Structure

The GNAS complex locus gene is located on the long (q) arm of chromosome 20 at position 13.3. The gene spans over 20,000 base pairs and consists of 13 exons. The GNAS complex locus gene encodes a 394 amino acid protein weighing approximately 45 kDa.

Function

The GNAS complex locus gene encodes the alpha subunit of the Gs protein, which is a heterotrimeric G protein. This protein is involved in transmitting signals from certain receptors on the outer surface of cells to the inside of the cell through a complex sequence of biochemical reactions. The Gs alpha subunit triggers the production of a molecule called cyclic AMP (cAMP), which transmits signals inside the cell.

Clinical significance

Mutations in the GNAS complex locus gene can lead to a variety of disorders. These include McCune-Albright syndrome, progressive osseous heteroplasia, pseudohypoparathyroidism types 1A and 1B, and Albright hereditary osteodystrophy. These conditions are characterized by a range of symptoms, including skeletal abnormalities, hormone imbalances, and in some cases, cognitive impairment.

See also

• G protein
• Adenylate cyclase
• Imprinted gene
• Chromosome 20
• McCune-Albright syndrome
• Progressive osseous heteroplasia
• Pseudohypoparathyroidism
• Albright hereditary osteodystrophy

External links

• GNAS complex locus at GeneCards