Titin, a huge, elastic sarcomeric protein with a probable role in morphogenesis

  title={Titin, a huge, elastic sarcomeric protein with a probable role in morphogenesis},
  author={Alice Bordwell Fulton and William B. Isaacs},
Titin, the largest protein identified to date (over 1 μm long, almost 3 million daltons in mass) is the third most abundant component of the sarcomere. In the mature myofibril, titin molecules span from M line to Z line, forming a third filament system which provides sarcomeric alignment and elastic recoil. In the developing sarcomere, accumulating evidence from studies both in vivo and in vitro implicates titin as part of a morphogenetic scaffolding, upon which critical events in… 

Immunoglobulin-type domains of titin: same fold, different stability?

The stability of the modules over a range of conditions was investigated by measuring key thermodynamic parameters for both thermal and chemical denaturation and by monitoring amide proton exchange as a function of time.

Structure and function of titin and nebulin.

  • T. Keller
  • Biology
    Current opinion in cell biology
  • 1995

Titin role in muscle homeostasis : the kinase domain

It was demonstrated that TK is a catalytically inactive pseudokinase acting as a molecular scaffold and TK and MuRF1 signaling modules are structurally interconnected and genetic perturbation of this link might lead to dilated cardiomyopathy.

Actin Motility

In vitro binding assays and electrophoretic analyses revealed that the inhibition is most likely caused by interaction between the actin filament and the titin 1-11 fragment, and the physiological relevance of the novel finding of motility inhibition by titin fragments is discussed.

Biochemical and Structural Properties of Titin , Nebulin and Intermediate Filaments in Muscle

The Z-line is a key structure of the myofibrils and of the overall skeletal muscle cell cytoskeleton and can be considered as “representing,” or taking the place of, the microfilaments of non-muscle cells.

Dissecting titin into its structural motifs: identification of an alpha-helix motif near the titin N-terminus.

A study of a stretch located in the titin N-terminus and part of a linker between two modules is presented, drawn toward this region because it shows 100% probability to form a coiled coil when analyzed by a prediction program.

Titin and Nebulin: Giant Multitasking Protein Rulers in Muscle

Recent studies of sarcomere-associated cytoskeletal lattices begin to shed light on how contracted muscle restores its length and how resting muscle responds to stretch and compression.



Titin is an extraordinarily long, flexible, and slender myofibrillar protein.

Electron microscopy of low-angle-shadowed and negatively stained specimens revealed that T2 chains self-assembled into extremely long, flexible, and extensible slender strands with axial periodicity, suggesting titin appears to be ideally suited as a component of an elastic lattice that serves as an organizing scaffold or template for thick and thin filaments.

Cytoskeletal matrix in striated muscle: the role of titin, nebulin and intermediate filaments.

  • K. Wang
  • Biology
    Advances in experimental medicine and biology
  • 1984
The recognition of the existence of two sets of sarcomere-associated cytoskeletal filaments within adult striated muscle fibers may be a significant step toward resolving some of the unsettled questions in muscle mechanics such as those that have been discussed in this meeting.

A physiological role for titin and nebulin in skeletal muscle

The ability of single skinned muscle cells to generate both passive tension in response to stretch and active tension in Response to calcium is greatly reduced after low doses of ionizing radiation, accompanied by axial misalignment of thick filaments.

Biosynthesis of titin in cultured skeletal muscle cells

Observations suggest that newly synthesized titin molecules are stable proteins that rapidly associate with the cytoskeleton of developing myotubes.

Sarcomere-Associated Cytoskeletal Lattices in Striated Muscle

The purpose of this chapter is to outline and develop key evidence that has led to the notion that the sarcomere contains two sets of distinct cytoskeletal filaments that are continuous and extensible.

A regular pattern of two types of 100-residue motif in the sequence of titin

It is shown that partial titin complementary DNAs encode a regular pattern of two types of 100-residue motif, each of which probably folds into a separate domain type.

A comparative study of high molecular weight proteins in various types of muscle across the animal kingdom.

A wide range of phyla have been surveyed by SDS-PAGE for the new large proteins of the myofibril, and Connectin (or titin) appears to be widely distributed and nebulin shares the same distribution in vertebrate muscles except for its notable absence in all heart muscle examined.

Connectin, an elastic protein of muscle. Identification of "titin" with connectin.

Studies of electrophoretic mobility on 2-3% polyacrylamide gel electrophoresis, amino acid composition, and localization in myofibrils determined by the indirect immunofluorescence technique showed that titin and connectin are identical.