Details

Autor(en) / Beteiligte

• Martin, Heather L.
• Turner, Amy L.
• Higgins, Julie
• Tang, Anna A.
• Tiede, Christian
• Taylor, Thomas
• Siripanthong, Sitthinon
• Adams, Thomas L.
• Manfield, Iain W.
• Bell, Sandra M.
• Morrison, Ewan E.
• Bond, Jacquelyn
• Trinh, Chi H.
• Hurst, Carolyn D.
• Knowles, Margaret A.
• Bayliss, Richard W.
• Tomlinson, Darren C.

Titel

Affimer-mediated locking of p21-activated kinase 5 in an intermediate activation state results in kinase inhibition

Ist Teil von

• Cell reports (Cambridge), 2023-10, Vol.42 (10), p.113184-113184, Article 113184

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Kinases are important therapeutic targets, and their inhibitors are classified according to their mechanism of action, which range from blocking ATP binding to covalent inhibition. Here, a mechanism of inhibition is highlighted by capturing p21-activated kinase 5 (PAK5) in an intermediate state of activation using an Affimer reagent that binds in the P+1 pocket. PAK5 was identified from a non-hypothesis-driven high-content imaging RNAi screen in urothelial cancer cells. Silencing of PAK5 resulted in reduced cell number, G1/S arrest, and enlargement of cells, suggesting it to be important in urothelial cancer cell line survival and proliferation. Affimer reagents were isolated to identify mechanisms of inhibition. The Affimer PAK5-Af17 recapitulated the phenotype seen with siRNA. Co-crystallization revealed that PAK5-Af17 bound in the P+1 pocket of PAK5, locking the kinase into a partial activation state. This mechanism of inhibition indicates that another class of kinase inhibitors is possible. [Display omitted] •PAK5 siRNA knockdown leads to G1/S arrest, cell enlargement, and reduced cell number•PAK5 inhibition with biologic, Affimer 17, mimics siRNA knockdown phenotype•Affimer 17 locks PAK5 in an intermediate activation state resulting in inhibition•Affimer 17 binding PAK5 Arg653 confers selectivity for PAK5 Martin et al. report that inhibition of p21 activated kinase 5 (PAK5) leads to G1/S transition arrest, cell enlargement, and reduced cell number. They identify a biologic inhibitor, Affimer 17, which locks PAK5 in a conformation representing an intermediate state of activation resulting in kinase inhibition.