6t5b
KRasG12C ligand complexKRasG12C ligand complex
Structural highlights
Disease[RASK_HUMAN] Defects in KRAS are a cause of acute myelogenous leukemia (AML) [MIM:601626]. AML is a malignant disease in which hematopoietic precursors are arrested in an early stage of development.[1] Defects in KRAS are a cause of juvenile myelomonocytic leukemia (JMML) [MIM:607785]. JMML is a pediatric myelodysplastic syndrome that constitutes approximately 30% of childhood cases of myelodysplastic syndrome (MDS) and 2% of leukemia. It is characterized by leukocytosis with tissue infiltration and in vitro hypersensitivity of myeloid progenitors to granulocyte-macrophage colony stimulating factor. Defects in KRAS are the cause of Noonan syndrome type 3 (NS3) [MIM:609942]. Noonan syndrome (NS) [MIM:163950] is a disorder characterized by dysmorphic facial features, short stature, hypertelorism, cardiac anomalies, deafness, motor delay, and a bleeding diathesis. It is a genetically heterogeneous and relatively common syndrome, with an estimated incidence of 1 in 1000-2500 live births. Rarely, NS is associated with juvenile myelomonocytic leukemia (JMML). NS3 inheritance is autosomal dominant.[2] [3] [4] [5] [6] [7] Defects in KRAS are a cause of gastric cancer (GASC) [MIM:613659]; also called gastric cancer intestinal or stomach cancer. Gastric cancer is a malignant disease which starts in the stomach, can spread to the esophagus or the small intestine, and can extend through the stomach wall to nearby lymph nodes and organs. It also can metastasize to other parts of the body. The term gastric cancer or gastric carcinoma refers to adenocarcinoma of the stomach that accounts for most of all gastric malignant tumors. Two main histologic types are recognized, diffuse type and intestinal type carcinomas. Diffuse tumors are poorly differentiated infiltrating lesions, resulting in thickening of the stomach. In contrast, intestinal tumors are usually exophytic, often ulcerating, and associated with intestinal metaplasia of the stomach, most often observed in sporadic disease.[8] [9] [10] Note=Defects in KRAS are a cause of pylocytic astrocytoma (PA). Pylocytic astrocytomas are neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors.[11] Defects in KRAS are a cause of cardiofaciocutaneous syndrome (CFC syndrome) [MIM:115150]; also known as cardio-facio-cutaneous syndrome. CFC syndrome is characterized by a distinctive facial appearance, heart defects and mental retardation. Heart defects include pulmonic stenosis, atrial septal defects and hypertrophic cardiomyopathy. Some affected individuals present with ectodermal abnormalities such as sparse, friable hair, hyperkeratotic skin lesions and a generalized ichthyosis-like condition. Typical facial features are similar to Noonan syndrome. They include high forehead with bitemporal constriction, hypoplastic supraorbital ridges, downslanting palpebral fissures, a depressed nasal bridge, and posteriorly angulated ears with prominent helices. The inheritance of CFC syndrome is autosomal dominant. Note=KRAS mutations are involved in cancer development. Function[RASK_HUMAN] Ras proteins bind GDP/GTP and possess intrinsic GTPase activity. Publication Abstract from PubMedAttempts to directly drug the important oncogene KRAS have met with limited success despite numerous efforts across industry and academia. The KRAS(G12C) mutant represents an "Achilles heel" and has recently yielded to covalent targeting with small molecules that bind the mutant cysteine and create an allosteric pocket on GDP-bound RAS, locking it in an inactive state. A weak inhibitor at this site was optimized through conformational locking of a piperazine-quinazoline motif and linker modification. Subsequent introduction of a key methyl group to the piperazine resulted in enhancements in potency, permeability, clearance, and reactivity, leading to identification of a potent KRAS(G12C) inhibitor with high selectivity and excellent cross-species pharmacokinetic parameters and in vivo efficacy. Structure-Based Design and Pharmacokinetic Optimization of Covalent Allosteric Inhibitors of the Mutant GTPase KRAS(G12C).,Kettle JG, Bagal SK, Bickerton S, Bodnarchuk MS, Breed J, Carbajo RJ, Cassar DJ, Chakraborty A, Cosulich S, Cumming I, Davies M, Eatherton A, Evans L, Feron L, Fillery S, Gleave ES, Goldberg FW, Harlfinger S, Hanson L, Howard M, Howells R, Jackson A, Kemmitt P, Kingston JK, Lamont S, Lewis HJ, Li S, Liu L, Ogg D, Phillips C, Polanski R, Robb G, Robinson D, Ross S, Smith JM, Tonge M, Whiteley R, Yang J, Zhang L, Zhao X J Med Chem. 2020 Feb 13. doi: 10.1021/acs.jmedchem.9b01720. PMID:32023060[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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