Codominant Expression

TLS Online TPP Program

#Id: 8411

#Section 3: Genetics, Cellular and Molecular Biology

In the absence of Ca2+, muscle is relaxed

TM blocks myosin’s interaction with F-actin

TLS Online TPP Program

#Id: 8410

#Section 3: Genetics, Cellular and Molecular Biology

TN-C is the calcium-binding subunit, controls the

position of TM on the surface of an actin filament through the TN-I and TN-T subunits

TLS Online TPP Program

#Id: 8409

#Section 3: Genetics, Cellular and Molecular Biology

Troponin, a complex of three polypeptides, 

TN-T (tropomyosin-binding)

TN-I  (inhibitory)

TN-C (Ca2+-binding)

TLS Online TPP Program

#Id: 8408

#Section 3: Genetics, Cellular and Molecular Biology

Tropomyosin (TM) is a ropelike molecule, about 40 nm in length, binds to 7 actin subunits in an actin filament.

TLS Online TPP Program

#Id: 8406

#Section 3: Genetics, Cellular and Molecular Biology

Vertebrate skeletal muscle contraction, also depends on set of specialized accessory proteins that are closely associated with the actin thin filaments:

a) Tropomyosin

b) Troponin

TLS Online TPP Program

#Id: 8405

#Section 3: Genetics, Cellular and Molecular Biology

Muscle contraction depends on two processes that consume enormous amounts of ATP: 

1. Filament sliding, driven by the ATPase of the myosin

2. Ca2+ pumping, driven by the Ca2+ ATPase