During cytokinesis, a small GTPase, RhoA, localizes to the equatorial membrane above the spindle midzone. The localization and activity of RhoA are potentially modulated by

A. RhoGEF Ect2

B. Aurora B kinase

C. PLK1 kinase

D. MKLP1 kinesin

E. ATM and ATR

Which of the following combinations contains all the correct statements?

Concept:

• Microtubules and RhoA activity are both necessary for the formation of the mitotic cleavage furrow.
• A microtubule-regulated exchange factor called GEF-H1 connects RhoA activation to microtubule dynamics.
   

Explanation:

• In vivo, MKLP1 forms a hetero tetrameric complex with MgcRacGAP through a unique interaction.
• In vitro, this complex rather than the individual part encourages antiparallel MicroTubule bundling.
• phosphorylation of MKLP1, by Aurora B kinase, has been suggested to regulate the time of midzone development .
• These findings imply that MKLP1 is a crucial component in the development of the midzone.
• During anaphase, the MKLP1 and MgcRacGAP-containing centralspindlin complex localises to the central spindle.
• The central spindle's ECT2 has a docking site for the RhoGEF, ECT2, thanks to PLK 1's phosphorylation of MgcRacGAP.
• At the equatorial cortex, ECT2 stimulates RhoA, which then sets off a downstream signaling cascade via Formins and Rho kinase that leads to the formation of an actomyosin ring, the ring is compressed, and two daughter cells are produced.
• Thus with the explanation above it is clear that components of statement A,B,C and D are capable of modulating activity of RhoA.​