The kinetics of Ras activation by Son of sevenless (SOS) changes profoundly when Ras is tethered to membranes, instead of being in solution. SOS has two binding sites for Ras, one of which is an allosteric site that is distal to the active site. The activity of the SOS catalytic unit (SOS(cat)) is up to 500-fold higher when Ras is on membranes compared to rates in solution, because the allosteric Ras site anchors SOS(cat) to the membrane. This effect is blocked by the N-terminal segment of SOS, which occludes the allosteric site. We show that SOS responds to the membrane density of Ras molecules, to their state of GTP loading and to the membrane concentration of phosphatidylinositol-4,5-bisphosphate (PIP2), and that the integration of these signals potentiates the release of autoinhibition.
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http://dx.doi.org/10.1038/nsmb.1418 | DOI Listing |
Eur J Med Chem
January 2025
Institute of Fine Organic Chemicals & Organic Materials, School of Chemistry and Chemical Engineering, Wuhan University of Science and Technology, Wuhan, 430081, PR China; School of Pharmaceutical Sciences, Guizhou University, Guiyang, 550025, PR China. Electronic address:
Small molecules that possess the ability to regulate the interactions between Son of Sevenless 1 (SOS1) and Kristen rat sarcoma (KRAS) offer immense potential in the realm of cancer therapy. In this study, we present a novel series of SOS1 inhibitors featuring a tricyclic quinazoline scaffold. Notably, we have identified compound 8d, which demonstrates the highest potency with an IC value of 5.
View Article and Find Full Text PDFOnco Targets Ther
November 2024
Department of Oncology, Central Hospital Affiliated to Shandong First Medical University, Jinan, Shandong Province, People's Republic of China.
In non-small cell lung cancer (NSCLC), Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations are found in up to 30% of all cases, with the most prevalent mutations occurring in codons 12 and 13. The development of -targeted drugs like sotorasib and adagrasib has generated significant excitement in the clinical arena, offering new therapeutic options. Their potential for combination with other treatments broadens the scope for clinical exploration.
View Article and Find Full Text PDFCytojournal
September 2024
Department of Gynaecology and Obstetrics, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China.
Adv Sci (Weinh)
November 2024
Department of Orthopedic Surgery, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510080, China.
Acquired resistance to hormonal therapy, particularly enzalutamide (ENZ), remains a significant obstacle in the treatment of advanced bone metastatic prostate cancer. Here, it is demonstrated that under ENZ treatment, osteoblasts in the bone microenvironment secrete increased levels of extracellular matrix protein 1 (ECM1), which affects surrounding prostate cancer cells, promoting tumor cell proliferation and anti-androgen resistance. Mechanistically, ECM1 interacts with the enolase 1 (ENO1) receptor on the prostate cancer cell membrane, leading to its phosphorylation at the Y189 site.
View Article and Find Full Text PDFJ Craniofac Surg
October 2024
Division of Plastic and Oral Surgery, Baylor Scott and White Medical Center and McLane Children's Hospital, Temple, TX.
Noonan syndrome (NS) is a rare, genetic multisystem disorder often presenting with associated craniofacial abnormalities. The authors report an identical twin pair with classical features of NS including short stature, mild ptosis, hypertelorism, down-slanting palpebral fissures, low-set angulated ears, and giant cell tumors in the craniofacial skeleton. Interestingly, these patients also presented with bilateral, symmetric, dystrophic auricular calcifications.
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