Actin: Difference between revisions

Jump to navigation Jump to search
Michal Harel (talk | contribs)
No edit summary
Michal Harel (talk | contribs)
No edit summary
Line 1: Line 1:
{{STRUCTURE_3hbt|  PDB=3hbt  | SIZE=400| SCENE=Actin/Cv/1 |right|CAPTION=Native G-actin with methyl-histidine complex with ATP, sulfate and Ca+2 ion (green) [[3hbt]] }}
{{STRUCTURE_3hbt|  PDB=3hbt  | SIZE=400| SCENE=Actin/Cv/1 |right|CAPTION=Native G-actin with methyl-histidine complex with ATP, sulfate and Ca+2 ion (green) [[3hbt]] }}


[[Actin]] is a protein found in all eukaryotic cells.  It is the monomer of two types of filaments: microfilaments which are part of the cytoskeleton and thin filaments which are part of muscles.  Three isoforms of actin are identified: α (Aa) (or G-actin) found in muscle tissue, β (Ab) and γ (Ag) actins  are components of the cytoskeleton.  F-actin is Aa bound to ATP. The images at the left and at the right correspond to one representative Actin, ''i.e.'' the crystal structure of rabbit Native G-actin ([[3hbt]]).  For more details see:<br /> *[[F-actin]]<br /> *[[Non-polymerizable monomeric actin]].<br /> <scene name='Actin/Cv/2'>Click here to see the difference between 2 conformations of bovine Ag actin</scene> (PDB entries [[1hlu]] and [[2btf]]; morph was taken from [http://molmovdb.org/cgi-bin/movie.cgi Gallery of Morphs] of the [http://molmovdb.org Yale Morph Server]).  
[[Actin]] is a protein found in all eukaryotic cells.  It is the monomer of two types of filaments: microfilaments which are part of the cytoskeleton and thin filaments which are part of muscles.  Three isoforms of actin are identified: α (Aa) (or G-actin) found in muscle tissue, β (Ab) and γ (Ag) actins  are components of the cytoskeleton.  F-actin is Aa bound to ATP.  For more details see:<br /> *[[F-actin]]<br /> *[[Non-polymerizable monomeric actin]].<br /> <scene name='Actin/Cv/2'>Click here to see the difference between 2 conformations of bovine Ag actin</scene> (PDB entries [[1hlu]] and [[2btf]]; morph was taken from [http://molmovdb.org/cgi-bin/movie.cgi Gallery of Morphs] of the [http://molmovdb.org Yale Morph Server]).
 
== Function ==
 
Actin participates in muscle contraction, cell motility, cell division and cytokinesis.  Actin associated with myosin is responsible for most cell movements.
 
== Disease ==
 
Mutations in α-actin found in skeletal striated muscles can cause myopathy.  Mutations in α-actin found in smooth muscles can cause thoracic aortic aneurism. Mutations in α-actin found in heart muscles can cause heart malfunctioning.
 
== Structural highlights ==
 
Actin binds ATP in a cleft.  It changes its conformation upon hydrolysis of its bound ATP to ADP.  Actin filaments are polar.  They are formed with all monomers having their clefts pointing in the same direction.


<br />
<br />

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Alexander Berchansky, Michal Harel, Joel L. Sussman