dynamin

The first structure on the left is dynamin in its relaxed state.

In mammals, three different dynamin genes have been identified:

It belongs to the dynamin superfamily of large GTPases.

See dynamin as a prototype for large GTPases.

In the brain, its primary function is thought to be the recruitment of dynamin to sites of clathrin-mediated endocytosis.

The Drp1 protein is a member of the Dynamin family of large GTPases.

For example, during high levels of neural activity, presynaptic intracellular calcium activates calcineurin which dephosphorylates dynamin.

The dephosphorylation of dynamin does not prevent the association of amphiphysin, therefore allowing the two processes to happen independently of each other.

To view a 'cartoon' image of the non-constricted and constricted state of dynamin spirals, please follow this link: http://dynamin.niddk.nih.gov/figure5.html.

A key protein required for endocytosis is dynamin: It assists in budding a coated pit into a cell to form a coated vesicle.

This shows the extent to which dynamin tightens and changes when GTP is converted to GDP.

Mutations in Dynamin II have been found to cause dominant intermediate Charcot-Marie-Tooth disease.

This condition is now known as dynamin 2 centronuclear myopathy (abbreviated DNM2-CNM).

The protein encoded by this gene is a member of the dynamin family which possess mechanochemical properties involved in actin-membrane processes, predominantly in membrane budding.

To view the effect of GTP and GDP on dynamin spirals, follow this link: http://dynamin.niddk.nih.gov/figure2.html.

Once the pit has been pinched off, the plasma membrane due to the actions of two other proteins called amphiphysin and dynamin, it is now an endocytic vesicle.

Recently, researchers discovered mutations at the gene dynamin 2 (DNM2 on chromosome 19, at site 19p13.2), responsible for the autosomal dominant form of centronuclear myopathy.

These include the GTPase dynamin, the lysophosphatidic acid acyl transferase endophilin, and the phosphoinositide phosphatase synaptojanin.

The EHD protein family comprises a group of protein that function in intracellular trafficking and that possess a dynamin like structural fold.

The GTPase dynamin then pinches off the large membrane-vacuole, which is either degraded or reused for synaptic vesicle production (possibly through clathrin coating).

In the periactive zone, scaffolding proteins such as intersectin 1 recruit proteins that mediate endocytotis such as dynamin, clathrin and endophilin.

Interactions from calcineurin activate dynamin GTPase activity, allowing the clathrin pit to excise itself from the cell membrane and become a cytoplasmic vesicle.

Dynamin appears to be playing a larger role in neurite formation because its vesicle pinching role and the possibility of it recycling plasma membrane and growth factor receptor proteins.

Fission of the vesicle from the plasma membrane is then mediated by GTPase dynamin II which is localized at the neck of the budding vesicle.

Mutations in the dynamin gene in which the activity of the dynamin protein is lost at above-normal temperatures (for the fly) exist: These are called temperature-sensitive mutations.