Many growth factors and cytokines are produced as larger precursors, containing prodomains, that require proteolytic processing to release the bioactive ligand. These prodomains can be significantly larger than the mature domains and can play an active role in the regulation of the ligands. Mining the UniProt database, we identified almost one hundred human growth factors and cytokines with pro-domains. These are spread across several unrelated protein families and vary in both their size and composition. Continue reading →
Anassuya Ramachandran, Merima Mehić, Laabiah Wasim, Dessislava Malinova, Ilaria Gori, Beata K Blaszczyk, Diana M Carvalho, Eileen M Shore, Chris Jones, Marko Hyvönen, Pavel Tolar, Caroline S Hill
Fibrodysplasia ossificans progressiva (FOP) and diffuse intrinsic pontine glioma (DIPG) are debilitating diseases that share causal mutations in ACVR1, a TGF-β family type I receptor. ACVR1R206H is a frequent mutation in both diseases. Pathogenic signaling via the SMAD1/5 pathway is mediated by Activin A, but how the mutation triggers aberrant signaling is not known. We show that ACVR1 is essential for Activin A-mediated SMAD1/5 phosphorylation and is activated by two distinct mechanisms. Wild-type ACVR1 is activated by the Activin type I receptors, ACVR1B/C. Continue reading →
Protein kinases are a large class of enzymes with numerous biological roles and many have been implicated in a vast array of diseases, including cancer and the novel coronavirus infection COVID-19. Thus, the development of chemical probes to selectively target each kinase is of great interest. Inhibition of protein kinases with ATP-competitive inhibitors has historically been the most widely used method. However, due to the highly conserved structures of ATP-sites, the identification of truly selective chemical probes is challenging. In this review, we use the Ser/Thr kinase CK2 as an example to highlight the historical challenges in effective and selective chemical probe development, alongside recent advances in the field and alternative strategies aiming to overcome these problems. Continue reading →
CK2 is a protein kinase that plays important roles in many physio-pathological cellular processes. As such, the development of chemical probes for CK2 has received increasing attention in the past decade with more than 40 lead compounds developed. In this review, we aim to provide the reader with a comprehensive overview of the chemical probes acting outside the highly-conserved ATP-site developed to date. Continue reading →
Duncan E. Scott, Nicola J. Francis-Newton, May E. Marsh, Anthony G. Coyne, Gerhard Fischer, Tommaso Moschetti, Andrew R. Bayly, Timothy D. Sharpe, Kalina T. Haas, Lorraine Barber, Chiara R. Valenzano, Rajavel Srinivasan, David J. Huggins, Miyoung Lee, Amy Emery, Bryn Hardwick, Matthias Ehebauer, Claudio Dagostin, Alessandro Esposito, Luca Pellegrini, Trevor Perrior, Grahame McKenzie, Tom L. Blundell, Marko Hyvönen, John Skidmore, Ashok R. Venkitaraman, Chris Abell
BRCA2 is a protein that helps the body fix broken DNA. It makes sure RAD51, works when the cell needs to fix broken DNA. Scientists made a new drug candidate, CAM833, that stops BRCA2 and RAD51 from working together. It can stop cancer cells from growing, especially when used together with other chemicals.
Abstract
BRCA2 controls RAD51 recombinase during homologous DNA recombination (HDR) through eight evolutionarily conserved BRC repeats, which individually engage RAD51 via the motif Phe-x-x-Ala. Using structure-guided molecular design, templated on a monomeric thermostable chimera between human RAD51 and archaeal RadA, we identify CAM833, a 529 Da orthosteric inhibitor of RAD51:BRC with a Kd of 366 nM. The quinoline of CAM833 occupies a hotspot, the Phe-binding pocket on RAD51 and the methyl of the substituted α-methylbenzyl group occupies the Ala-binding pocket. Continue reading →
Angelos Papadopoulos, Varvara Chalmantzi, Olga Mikhaylichenko, Marko Hyvönen, Dimitris Stellas, Aditi Kanhere, John Heath, Debbie L Cunningham, Theodore Fotsis, Carol Murphy
Human embryonic stem cells (hESCs) are an invaluable tool in the fields of embryology and regenerative medicine. Activin A and BMP4 are well-characterised growth factors implicated in pluripotency and differentiation. In the current study, hESCs are cultured in a modified version of mTeSR1, where low concentrations of Activin A substitute for TGFβ. This culture system is further used to investigate the changes induced by BMP4 on hESCs by employing a combination of transcriptomic and phosphoproteomic approaches. Results indicate that in a pluripotent state, hESCs maintain WNT signaling under negative regulation by expressing pathway inhibitors. Continue reading →
CK2α is a ubiquitous, well-studied kinase that is a target for small-molecule inhibition, for treatment of cancers. While many different classes of ATP-competitive inhibitors have been described for CK2α, they tend to suffer from significant off-target activity and new approaches are needed. A series of inhibitors of CK2α has recently been described as allosteric, acting at a previously unidentified binding site. Given the similarity of these inhibitors to known ATP-competitive inhibitors, we have investigated these further. In our thorough structural and biophysical analyses, we have found no evidence that these inhibitors bind to the proposed allosteric site. Continue reading →
Takuhiro Sonoyama, Lukas K J Stadler, Mingyan Zhu, Julia M Keogh, Elana Henning, Fuki Hisama, Peter Kirwan, Magdalena Jura, Beata K Blaszczyk, David C DeWitt, Bas Brouwers, Marko Hyvönen, Inês Barroso, Florian T Merkle, Suzanne M Appleyard, Gary A Wayman, I Sadaf Farooqi
Brain-derived neurotrophic factor (BDNF) signals through its high affinity receptor Tropomyosin receptor kinase-B (TrkB) to regulate neuronal development, synapse formation and plasticity. In rodents, genetic disruption of Bdnf and TrkB leads to weight gain and a spectrum of neurobehavioural phenotypes. Here, we functionally characterised a de novo missense variant in BDNF and seven rare variants in TrkB identified in a large cohort of people with severe, childhood-onset obesity. Continue reading →
Bone morphogenetic proteins (BMPs) are multifunctional secreted cytokines that act in a highly context-dependent manner. BMP action extends beyond the induction of cartilage and bone formation, to encompass pivotal roles in controlling tissue and organ homeostasis during development and adulthood. BMPs signal via plasma membrane type I and type II serine/threonine kinase receptors and intracellular SMAD transcriptional effectors. Exquisite temporospatial control of BMP/SMAD signalling and crosstalk with other cellular cues is achieved by a series of positive and negative regulators at each step in the BMP/SMAD pathway. Continue reading →
Sarah L. Kidd, Elaine Fowler, Till Reinhardt, Thomas Compton, Natalia Mateu, Hector Newman, Dom Bellini, Romain Talon, Joseph McLoughlin, Tobias Krojer, Anthony Aimon, Anthony Bradley, Michael Fairhead, Paul Brear, Laura Díaz-Sáez, Katherine McAuley, Hannah F. Sore, Andrew Madin, Daniel H. O’Donovan, Kilian V. M. Huber, Marko Hyvönen, Frank von Delft, Christopher G. Dowson and David R. Spring
Organic synthesis underpins the evolution of weak fragment hits into potent lead compounds. Deficiencies within current screening collections often result in the requirement of significant synthetic investment to enable multidirectional fragment growth, limiting the efficiency of the hit evolution process. Diversity-oriented synthesis (DOS)-derived fragment libraries are constructed in an efficient and modular fashion and thus are well-suited to address this challenge. To demonstrate the effective nature of such libraries within fragment-based drug discovery, we herein describe the screening of a 40-member DOS library against three functionally distinct biological targets using X-Ray crystallography. Continue reading →
