Where is GM2 found?
Ganglioside GM2 is abundant in cells of the central nervous system and accumulates within the lysosomes of neurons and macrophages.
How is GM2 ganglioside made?
Glycosphingolipids including these gangliosides are primarily synthesized in the endoplasmic reticulum and further modified in the Golgi apparatus by sequential addition of additional carbohydrate moieties3) to an existing acceptor lipid molecule. The reaction is catalyzed by a series of specific glycosyltransferases.
How are gangliosides broken down?
Ganglioside GM2 is degraded in the lysosome by β-hexosaminidase A. This enzyme removes the terminal N-acetylgalactosaminyl residue. The enzyme requires the presence of an additional protein termed ‘GM2 activator’ encoded by the GM2A gene.
What is the purpose of GM2?
Normal Function The GM2A gene provides instructions for making a protein called the GM2 ganglioside activator. This protein is necessary for the normal function of an enzyme called beta-hexosaminidase A, which plays a critical role in the brain and spinal cord (central nervous system).
What is the meaning of GM2?
GM2 is a type of ganglioside. G refers to ganglioside, the M is for monosialic (as in it has one sialic acid), and 2 refers to the fact that it was the second monosialic ganglioside discovered. It is associated with GM2 gangliosidoses such as Tay–Sachs disease.
Why is GM2 ganglioside toxic?
Without the GM2 ganglioside activator, beta-hexosaminidase A is unable to break down GM2 ganglioside. As a result, this substance builds up to toxic levels, particularly in nerve cells in the brain and spinal cord.
What is the difference between GM1 and GM2?
GM1 gangliosidosis has both central nervous system and systemic findings; while, GM2 gangliosidosis is restricted primarily to the central nervous system. Both disorders have autosomal recessive modes of inheritance and a continuum of clinical presentations from a severe infantile form to a milder, chronic adult form.
What do gangliosides do?
Gangliosides are enriched in cell membrane microdomains (“lipid rafts”) and play important roles in the modulation of membrane proteins and ion channels, in cell signaling and in the communication among cells.
What is the function of GM2 gangliosides?
Why is GM2 toxic?
Mutations in the GM2A gene disrupt the activity of the GM2 ganglioside activator, which prevents beta-hexosaminidase A from breaking down GM2 ganglioside. As a result, this substance accumulates to toxic levels, particularly in neurons in the brain and spinal cord.
What do GM2 gangliosides do?
What is GM1 and GM2?