PMID: 21117080

Authors:

Tsui V, Gibbons P, Ultsch M, Mortara K, Chang C, Blair W, Pulk R, Stanley M, Starovasnik M, Williams D, Lamers M, Leonard P, Magnuson S, Liang J, Eigenbrot C

Title:

A new regulatory switch in a JAK protein kinase.

Journal:

Proteins. 2010 Oct 7.

Abstract:

Members of the JAK family of protein kinases mediate signal transduction from cytokine receptors to transcription factor activation. Over-stimulation of these pathways is causative in immune disorders like rheumatoid arthritis, psoriasis, lupus, and Crohn's disease. A search for selective inhibitors of a JAK kinase has led to our characterization of a previously unknown kinase conformation arising from presentation of Tyr962 of TYK2 to an inhibitory small molecule via an H-bonding interaction. A small minority of protein kinase domains has a Tyrosine residue in this position within the alphaC-beta4 loop, and it is the only amino acid commonly seen here with H-bonding potential. These discoveries will aid design of inhibitors that discriminate among the JAK family and more widely among protein kinases. Proteins 2010. (c) 2010 Wiley-Liss, Inc.