
The muniscin protein family was initially defined in 2009
as proteins having 2 homologous domains that are involved in
clathrin
Clathrin is a protein that plays a major role in the formation of coated vesicles. Clathrin was first isolated and named by Barbara Pearse in 1976. It forms a triskelion shape composed of three clathrin heavy chains and three light chains. Wh ...
mediated
endocytosis
Endocytosis is a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material. E ...
(CME) and have been reviewed.
In addition to
FCHO1,
FCHO2 and Syp1,
SGIP1 is also included in the family because it contains the
μ (mu) homology domain and is involved in CME, even though it does not contain the
F-BAR domain
Muniscins are known as alternate cargo adaptors. That is, they participate in selecting which cargo molecules are internalized via CME.
Additionally, the structure of the dimer, with its concave face oriented toward the plasma membrane, is thought to help curve the membrane as the clathrin coated pit forms.
The muniscins are early arriving proteins involved in CME.
FCHO proteins are required for CME,
but do not appear to be required to ''initiate'' CME.
The μ homology domain of muniscins has been reported to have evolved from part of an ancient cargo adaptor protein complex named TSET.
See also
*
AP2 adaptor complex The AP2 adaptor complex is a multimeric protein that works on the cell membrane to internalize cargo in clathrin-mediated endocytosis. It is a stable complex of four adaptins which give rise to a structure that has a core domain and two appendage ...
*
Vesicular transport adaptor protein
Vesicular transport adaptor proteins are proteins involved in forming complexes that function in the trafficking of molecules from one subcellular location to another. These complexes concentrate the correct cargo molecules in vesicles that bud ...
References
{{Reflist
Peripheral membrane proteins
Protein complexes
Protein families
Molecular evolution
Vesicular transport proteins