Understanding the Conformational Changes of Kinesin‐5

Abstract

Human Kinesin‐5 (Eg5), an anticancer drug target, is key to the assembly of the bipolar spindle during mitosis. Its promise as a clinical target comes from the fact that it is involved only in metaphase and not interphase like some of the leading clinical drugs; however, the overall mechanism of inhibition needs further exploration. Inspection of the crystal structures of Kinesin‐1 dimers reveal the addition of strands to the central β‐sheet is found in one head and absent in the other; this previously unrecognized structural asymmetry between the two heads may suggest a regulatory mechanism involving the N‐terminal Neck‐Linker (NL) and the C‐Terminal Cover‐Neck. These structural changes in the neck‐linker and cover‐neck of Kinesin‐5 have not been reported. Thus, the importance of establishing this conformational switch in Kinesin‐5 requires additional experiments for understanding and molecular validation. But first, we must understand how changes in the neck‐linker modulate kinesin function. We have inserted three residues (+DAL) into the middle of the neck‐linker of dimeric Kinesin‐5 (1‐513) and KHC (1‐560). Our results indicate these neck‐linker mutants can allosterically regulate kinesin ATPase activity. Our future goal is to test the response to inhibition by current anticancer inhibitors such as S‐trityl‐L‐cysteine.Support or Funding InformationBUILD Technicians supported under grant #RL5GM118966 and BUILD undergraduate students under grant #TL4GM118968. An Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant #5 P20 GM103424‐15 and 3 P20 GM103424‐15S1. The Louisiana Cancer Research Consortium (LCRC) and National Center for Research Resources RCMI program Grant #8 G12MD007595 and the Louisiana Biomedical Research Network Grant #8P20GM103424. The National Institute of Minority Health and Health Disparities of the National Institutes of Health under award #G12MD007595. Students are supported by GRAD Star Scholar Mini Grants through Center for Undergraduate Research and Graduate Opportunity (CURGO).