What Makes a Kinase Promiscuous for Inhibitors?

Area of Science:

• Biochemistry
• Structural Biology
• Pharmacology

Background:

• ATP-competitive kinase inhibitors often exhibit promiscuity due to conserved ATP-binding pockets across kinases.
• Kinome-wide profiling data reveals a subset of kinases are disproportionately targeted by inhibitors.

Purpose of the Study:

• To investigate the structural basis for promiscuous inhibitor binding in kinases.
• To understand why certain kinases bind a higher number of inhibitors.

Main Methods:

• Clustering analysis of kinome profiling data.
• Co-crystal structure determination of DDR1 with inhibitors dasatinib and VX-680.
• Computational and biochemical assays to assess kinase conformation and stability.

Main Results:

• Identified a cluster of eight highly promiscuous kinases.
• DDR1 unexpectedly binds type I inhibitors in an inactive conformation.
• DDR1 exhibits unusual stability in this inactive conformation.

Conclusions:

• The stability of DDR1 in an inactive conformation provides a mechanistic explanation for its promiscuity with type I inhibitors.
• Phenotypic clustering offers functional insights beyond sequence homology.
• This work advances understanding of kinase inhibitor interactions and promiscuity.