RasIns: Genetically Encoded Intrabodies of Activated Ras Proteins
Autor: | Daniel Krieger, Mehmet Cetin, Don B. Arnold, Farzad Jalali-Yazdi, Richard W. Roberts, Terry T. Takahashi, Garrett G. Gross, William E. Evenson |
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Rok vydání: | 2017 |
Předmět: |
0301 basic medicine
GTP' Protein Conformation Mutant Biology Guanosine Diphosphate Antibodies Article Intrabody Affinity maturation 03 medical and health sciences Structural Biology Chlorocebus aethiops Animals Humans mRNA display Amino Acid Sequence RNA Messenger Molecular Biology Gene COS cells High-Throughput Nucleotide Sequencing Phenotype Molecular biology Cell biology 030104 developmental biology COS Cells Mutation ras Proteins biology.protein Guanosine Triphosphate Signal Transduction |
Zdroj: | Journal of Molecular Biology |
ISSN: | 0022-2836 |
DOI: | 10.1016/j.jmb.2016.11.008 |
Popis: | K- and H-Ras are the most commonly mutated genes in human tumors and are critical for conferring and maintaining the oncogenic phenotype in tumors with poor prognoses. Here, we design genetically encoded antibody-like ligands (intrabodies) that recognize active, GTP-bound K- and H-Ras. These ligands, which use the 10th domain of human fibronectin as their scaffold, are stable inside the cells and when fused with a fluorescent protein label, the constitutively active G12V mutant H-Ras. Primary selection of ligands against Ras with mRNA display resulted in an intrabody (termed RasIn1) that binds with a K D of 2.1 μM to H-Ras(G12V) (GTP), excellent state selectivity, and remarkable specificity for K- and H-Ras. RasIn1 recognizes residues in the Switch I region of Ras, similar to Raf-RBD, and competes with Raf-RBD for binding. An affinity maturation selection based on RasIn1 resulted in RasIn2, which binds with a K D of 120 nM and also retains excellent state selectivity. Both of these intrabodies colocalize with H-Ras, K-Ras, and G12V mutants inside the cells, providing new potential tools to monitor and modulate Ras-mediated signaling. Finally, RasIn1 and Rasin2 both display selectivity for the G12V mutants as compared with wild-type Ras providing a potential route for mutant selective recognition of Ras. |
Databáze: | OpenAIRE |
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