Characterisation of a cyclic peptide that binds to the RAS binding domain of phosphoinositide 3-kinase p110 alpha
Date
2023-02-02ICR Author
Author
Ismail, M
Martin, SR
George, R
Houghton, F
Kelly, G
Chaleil, RAG
Anastasiou, P
Wang, X
O'Reilly, N
Federico, S
Joshi, D
Nagaraj, H
Cooley, R
Hui, NS
Molina-Arcas, M
Hancock, DC
Tavassoli, A
Downward, J
Type
Journal Article
Metadata
Show full item recordAbstract
<jats:title>Abstract</jats:title><jats:p>P110α is a member of the phosphoinositide 3-kinase (PI3K) enzyme family that functions downstream of RAS. RAS proteins contribute to the activation of p110α by interacting directly with its RAS binding domain (RBD), resulting in the promotion of many cellular functions such as cell growth, proliferation and survival. Previous work from our lab has highlighted the importance of the p110α/RAS interaction in tumour initiation and growth. Here we report the discovery and characterisation of a cyclic peptide inhibitor (cyclo-CRVLIR) that interacts with the p110α-RBD and blocks its interaction with KRAS. cyclo-CRVLIR was discovered by screening a “split-intein cyclisation of peptides and proteins” (SICLOPPS) cyclic peptide library. The primary cyclic peptide hit from the screen initially showed a weak affinity for the p110α-RBD (K<jats:sub>d</jats:sub> about 360 µM). However, two rounds of amino acid substitution led to cyclo-CRVLIR, with an improved affinity for p110α-RBD in the low µM (K<jats:sub>d</jats:sub> 3 µM). We show that cyclo-CRVLIR binds selectively to the p110α-RBD but not to KRAS or the structurally-related RAF-RBD. Further, using biophysical, biochemical and cellular assays, we show that cyclo-CRVLIR effectively blocks the p110α/KRAS interaction in a dose dependent manner and reduces phospho-AKT levels in several oncogenic KRAS cell lines.</jats:p>
Collections
Subject
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
CRYSTAL-STRUCTURE
PI3K
LIBRARIES
INHIBITION
DISCOVERY
SWARMDOCK
PROTEINS
KINASE
MUTANT
Research team
RNA Bio & Mol Therap
Lung Cancer Group
Language
eng
Date accepted
2023-01-24
License start date
2023-02-02
Citation
Scientific Reports, 2023, 13 (1),
Publisher
NATURE PORTFOLIO