From the Research
The defective organelle in a cell with deficient glycosylation would be the Golgi apparatus, as well as the endoplasmic reticulum and cytosol, as these are the primary locations where glycosylation defects can occur, as indicated by the most recent study 1. The Golgi apparatus is primarily responsible for processing, sorting, and modifying proteins after they are synthesized in the endoplasmic reticulum, with glycosylation being one of its key functions. Glycosylation is the process of adding sugar molecules to proteins and lipids, which is essential for proper protein folding, stability, and function. When glycosylation is deficient, it indicates that the Golgi apparatus, as well as the endoplasmic reticulum and cytosol, are not functioning properly. The key points to consider are:
- The Golgi apparatus contains various glycosyltransferase enzymes that add specific sugar residues to proteins in a sequential manner.
- Defects in these enzymes or in the structure of the Golgi itself can lead to abnormal glycosylation patterns.
- Disorders of glycosylation in humans, known as Congenital Disorders of Glycosylation (CDGs), often present with multisystemic symptoms due to the fundamental role of glycoproteins throughout the body, as discussed in 2, 3, 4, 5.
- CDGs can affect nearly all organs and systems, and the considerable variability of clinical features makes it difficult to recognize patients with CDG, as noted in 3.
- Biochemical and genetic testing bear particularly important and complementary diagnostic roles in CDG, as highlighted in 1.