In Which of the Following Structures are Actin-Myosin II Bundles

Question

In which of the following structures are actin-myosin II bundles regulated by the troponin complex?
A) Stress fiber
B) Circumferential belt
C) Contractile ring
D) Adherens junction
E) None of the above

Accepted Answer

The troponin complex regulates the contraction of sarcomeres in skeletal and heart muscle cells. Non-muscle contractile bundles are regulated by myosin phosphorylation.