Tropomodulin (TMOD) is a protein which binds and caps the minus end of

actin Actin is a protein family, family of Globular protein, globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in myofibril, muscle fibrils. It is found in essentially all Eukaryote, eukaryotic cel ...

(the "pointed" end), regulating the length of

filaments in

muscle Skeletal muscles (commonly referred to as muscles) are Organ (biology), organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other ...

and non-muscle cells. The protein functions by physically blocking the spontaneous dissociation of

ADP Adp or ADP may refer to: Aviation * Aéroports de Paris, airport authority for the Parisian region in France * Aeropuertos del Perú, airport operator for airports in northern Peru * SLAF Anuradhapura, an airport in Sri Lanka * Ampara Air ...

-bound actin monomers from the minus end of the actin fibre. This, along with plus end capping proteins, such as

capZ CapZ, also known as CAPZ, CAZ1 and CAPPA1, is a capping protein that caps the barbed end of actin filaments in muscle cells. Structure CapZ is a heterodimeric molecule, made up of an α and β subunit. The α and β subunits are similar in struct ...

stabilise the structure of the actin filament. End capping is particularly important when long-lived actin filaments are necessary, for example: in

myofibrils A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. Each myof ...

. Inhibition of tropomodulin capping activity leads to dramatic increase in thin filament length from its pointed end.

Genes

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TMOD1 Tropomodulin-1 is a protein that in humans is encoded by the ''TMOD1'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth' ...

'' *''

TMOD2 Tropomodulin 2 (neuronal) also known as TMOD2 is a protein which in humans is encoded by the ''TMOD2'' gene. Function This gene encodes a neuronal-specific member of the tropomodulin family of actin-regulatory proteins. The encoded protein c ...

'' *''

TMOD3 Tropomodulin-3 is a protein that in humans is encoded by the ''TMOD3'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birt ...

'' *'' TMOD4''

References

External links

* {{protein-stub