Centrins, also known as caltractins, are a family of
calcium-binding
phosphoproteins found in the
centrosome of
eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...
s. Centrins are present in the
centriole
In cell biology a centriole is a cylindrical organelle composed mainly of a protein called tubulin. Centrioles are found in most eukaryotic cells, but are not present in conifers (Pinophyta), flowering plants (angiosperms) and most fungi, and a ...
s and pericentriolar lattice.
Human centrin genes are
CETN1
Centrin-1 is a protein that in humans is encoded by the ''CETN1'' gene. It belongs to the centrin
Centrins, also known as caltractins, are a family of calcium-binding phosphoproteins found in the centrosome of eukaryotes. Centrins are present in ...
,
CETN2
Centrin-2 is a protein that in humans is encoded by the ''CETN2'' gene. It belongs to the centrin family of proteins.
Centrin-2 belongs to a family of calcium-binding proteins and is a structural component of the centrosome. The high level of co ...
and
CETN3
Centrin-3 is a protein that in humans is encoded by the ''CETN3'' gene. It belongs to the centrin
Centrins, also known as caltractins, are a family of calcium-binding phosphoproteins found in the centrosome of eukaryotes. Centrins are present i ...
.
History
Centrin was first isolated and characterized from the flagellar roots
of the green alga ''
Tetraselmis striata
''Tetraselmis'' is a genus of phytoplankton. ''Tetraselmis'' is a green algal genus within the order Chlorodendrales, and they are characterized by their intensely-colored green chloroplast, their flagellated cell bodies, the presence of a pyren ...
'' in 1984.
Function
Centrins are required for duplication of centrioles.
They may also play a role in severing of
microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 an ...
s by causing calcium-mediated contraction.
The majority of centrin in the cell is non-centrosomal whose function is not yet clear.
Structure
Centrin belongs to the
EF-hand superfamily of calcium-binding proteins and has four calcium-binding EF-hands.
It has a molecular weight of 20 kDa.
See also
*
Centriole
In cell biology a centriole is a cylindrical organelle composed mainly of a protein called tubulin. Centrioles are found in most eukaryotic cells, but are not present in conifers (Pinophyta), flowering plants (angiosperms) and most fungi, and a ...
*
Centrosome
References
Protein families
{{protein-stub