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A Guide to Production, Crystallization, and Structure Determination of Human IKK1/α
Published on: November 2, 2018
Crystal structure of human vaccinia-related kinase 1 in complex with AMP-PNP, a non-hydrolyzable ATP analog
Yeen Shian Ngow1, Sreekanth Rajan1, Hong Ye1
1School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
Abstract:
Vaccinia-related kinase 1 (VRK1), a serine/threonine mitotic kinase, is widely over-expressed in dividing cells and regarded as a cancer drug target primarily due to its function as an early response gene in cell proliferation. However, the mechanism of VRK1 phosphorylation and substrate activation is not well understood. More importantly even the molecular basis of VRK1 interaction with its cofactor, adenosine triphosphate (ATP), is unavailable to-date. As designing specific inhibitors remains to be the major challenge in kinase research, such a molecular understanding will enable us to design ATP-competitive specific inhibitors of VRK1. Here we report the molecular characterization of VRK1 in complex with AMP-PNP, a non-hydrolyzable ATP-analog, using NMR titration followed by the co-crystal structure determined upto 2.07 Å resolution. We also carried out the structural comparison of the AMP-PNP bound-form with its apo and inhibitor-bound counterparts, which has enabled us to present our rationale toward designing VRK1-specific inhibitors.
Insights
Vaccinia-related kinase 1 (VRK1) is a cancer target, but its ATP binding was unknown. We determined the VRK1-ATP analog structure, aiding the design of specific VRK1 inhibitors.
Area of Science:
- Biochemistry
- Structural Biology
- Cancer Research
Background:
- Vaccinia-related kinase 1 (VRK1) is a serine/threonine kinase over-expressed in cancer cells.
- VRK1 is an early response gene in cell proliferation and a potential cancer drug target.
- The molecular mechanisms of VRK1 phosphorylation, substrate activation, and ATP binding are poorly understood.
Purpose of the Study:
- To elucidate the molecular basis of VRK1 interaction with adenosine triphosphate (ATP).
- To provide a structural understanding for designing specific ATP-competitive VRK1 inhibitors.
Main Methods:
- Nuclear Magnetic Resonance (NMR) titration to study VRK1 in complex with AMP-PNP (an ATP analog).
- X-ray crystallography to determine the co-crystal structure of VRK1-AMP-PNP at 2.07 Å resolution.
- Comparative structural analysis of VRK1 in apo, AMP-PNP-bound, and inhibitor-bound states.
Main Results:
- The molecular characterization of VRK1 in complex with AMP-PNP was achieved.
- The co-crystal structure revealed the binding mode of the ATP analog.
- Structural comparisons provided insights into VRK1 conformational changes and inhibitor interactions.
Conclusions:
- The determined structure provides critical insights into VRK1 ATP binding.
- This molecular understanding is essential for the rational design of VRK1-specific inhibitors.
- Targeting VRK1 could offer a new therapeutic strategy for cancer treatment.
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