Question

The pathogen Listeria monocytogenes can hijack the actin cytoskeleton in human cells and spread inside the host. Indicate true (T) and false (F) statements below about this phenomenon. Your answer would be a four-letter string composed of letters T and F only; e.g. TTFF.

(A) The movement can be reconstituted in vitro by placing the bacteria in a mixture of actin, formin, gelsolin, and capping protein.
(B) Cofilin counteracts the movement by depolymerizing actin filaments.
(C) The actin filaments grow with their minus ends pointed toward the bacterium.
(D) The movement depends on myosin activity to transport the bacteria on the actin filaments.

Answer 1

The correct statements about the phenomenon of Listeria monocytogenes hijacking the actin cytoskeleton in human cells are: Cofilin counteracts the movement by depolymerizing actin filaments, and The movement depends on myosin activity to transport the bacteria on the actin filaments.

Step-by-step explanation:

The correct answer is TFTF.

(A) The movement can be reconstituted in vitro by placing the bacteria in a mixture of actin, formin, gelsolin, and capping protein. This statement is false. Listeria monocytogenes can hijack the actin cytoskeleton in human cells, but it cannot be reconstituted in vitro with a mixture of actin and other proteins.

(B) Cofilin counteracts the movement by depolymerizing actin filaments. This statement is true. Cofilin is a protein that depolymerizes actin filaments, thereby counteracting the movement of Listeria monocytogenes.

(C) The actin filaments grow with their minus ends pointed toward the bacterium. This statement is false. The actin filaments grow with their plus ends pointed toward the bacterium.

(D) The movement depends on myosin activity to transport the bacteria on the actin filaments. This statement is true. Myosin activity is required to transport Listeria monocytogenes on the actin filaments.