Tropomodulin
Encyclopedia
Tropomodulin is a protein which binds and caps the minus end of actin
(the "pointed" end), regulating the length of actin
filaments in muscle
and non-muscle cells. The protein functions by physically blocking the spontaneous dissociation of GDP bound actin monomers from the minus end of the actin fibre. This, along with plus end capping proteins, such as capZ
stabilise the structure of the actin filament. End capping is particularly important when long lived actin filaments are necessary, for example: in myofibrils. Inhibition of tropomodulin capping activity leads to dramatic increase in thin filament length from its pointed end.
Actin
Actin is a globular, roughly 42-kDa moonlighting protein found in all eukaryotic cells where it may be present at concentrations of over 100 μM. It is also one of the most highly-conserved proteins, differing by no more than 20% in species as diverse as algae and humans...
(the "pointed" end), regulating the length of actin
Actin
Actin is a globular, roughly 42-kDa moonlighting protein found in all eukaryotic cells where it may be present at concentrations of over 100 μM. It is also one of the most highly-conserved proteins, differing by no more than 20% in species as diverse as algae and humans...
filaments in muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
and non-muscle cells. The protein functions by physically blocking the spontaneous dissociation of GDP bound actin monomers from the minus end of the actin fibre. This, along with plus end capping proteins, such as capZ
CapZ
CapZ is a protein that caps the barbed end of actin filaments in muscle cells. It is located in the muscle Z band....
stabilise the structure of the actin filament. End capping is particularly important when long lived actin filaments are necessary, for example: in myofibrils. Inhibition of tropomodulin capping activity leads to dramatic increase in thin filament length from its pointed end.