The Hippo pathway has been implicated in suppressing tissue overgrowth and tumor formation by restricting the oncogenic activity of YAP. However, transcriptional regulators that inhibit YAP activity have not been well studied. Here, we uncover clinical importance for VGLL4 in gastric cancer suppression and find that VGLL4 directly competes with YAP for binding TEADs. Importantly, VGLL4's tandem Tondu domains are not only essential but also sufficient for its inhibitory activity toward YAP. A peptide mimicking this function of VGLL4 potently suppressed tumor growth in vitro and in vivo. These findings suggest that disruption of YAP-TEADs interaction by a VGLL4-mimicking peptide may be a promising therapeutic strategy against YAP-driven human cancers.
Hedgehog (HH) morphogen is essential for metazoan development. The seven-transmembrane protein smoothened (SMO) transduces the HH signal across the plasma membrane, but how SMO is activated remains poorly understood. In Drosophila melanogaster, HH induces phosphorylation at multiple Ser/Thr residues in the SMO carboxy-terminal cytoplasmic tail, leading to its cell surface accumulation and activation. Here we provide evidence that phosphorylation activates SMO by inducing a conformational switch. This occurs by antagonizing multiple Arg clusters in the SMO cytoplasmic tail. The Arg clusters inhibit SMO by blocking its cell surface expression and keeping it in an inactive conformation that is maintained by intramolecular electrostatic interactions. HH-induced phosphorylation disrupts the interaction, and induces a conformational switch and dimerization of SMO cytoplasmic tails, which is essential for pathway activation. Increasing the number of mutations in the Arg clusters progressively activates SMO. Hence, by employing multiple Arg clusters as inhibitory elements counteracted by differential phosphorylation, SMO acts as a rheostat to translate graded HH signals into distinct responses.The HH morphogen controls many key development processes, with different thresholds specifying distinct outcomes [1][2][3][4] . In Drosophila wing discs, HH proteins secreted by posterior (P) compartment cells move into the anterior (A) compartment to form a local concentration gradient 5,6 . Low levels of HH suffice to induce the expression of decapentaplegic (dpp), whereas high levels are required to induce patched (ptc) and engrailed (en) ( Supplementary Fig. 1) [7][8][9] .The reception system for HH consists of a twelve-transmembrane protein, PTC, as the HH receptor and a seven-transmembrane protein smoothened (SMO) as the signal transducer 10-13 . In Drosophila, HH binding to PTC abrogates its inhibition on SMO and induces extensive phosphorylation of the SMO cytoplasmic tail by protein kinase A (PKA) and casein kinase I (CKI), leading to SMO cell surface accumulation and activation [14][15][16][17] . How phosphorylation promotes SMO cell surface accumulation is not understood. In addition, phosphorylation may regulate SMO activity through mechanism(s) other than controlling its cell surface abundance. Regulation of SMO by multiple Arg clustersOur previous study indicates that phosphorylation may regulate SMO cell surface abundance by either preventing its endocytosis and/or promoting its recycling 15 . To investigate further how SMO cell surface expression is regulated, we generated a set of C-terminally truncated SMO variants and examined their subcellular localization using a cell-based assay (Fig. 1). Deletion up to amino acid 818 did not significantly change SMO subcellular distribution; however, further deletions resulted in progressively increased cell surface expression (Fig. 1a, c), implying that multiple negative regulatory elements exist between amino acids 661-818.SMODC710 exhibits consistently higher cell surface...
A variety of organisms have evolved mechanisms to detect and respond to light, in which the response is mediated by protein structural changes following photon absorption. The initial step is often the photo-isomerization of a conjugated chromophore. Isomerization occurs on ultrafast timescales, and is substantially influenced by the chromophore environment. Here we identify structural changes associated with the earliest steps in the trans to cis isomerization of the chromophore in photoactive yellow protein. Femtosecond, hard X-ray pulses emitted by the Linac Coherent Light Source were used to conduct time-resolved serial femtosecond crystallography on PYP microcrystals over the time range from 100 femtoseconds to 3 picoseconds to determine the structural dynamics of the photoisomerization reaction.
antagonist ͉ cancer ͉ Gli ͉ medulloblastoma
Hedgehog (Hh) proteins control animal development by regulating the Gli/Ci family of transcription factors. In Drosophila, Hh counteracts phosphorylation by PKA, GSK3, and CKI to prevent Cubitus interruptus (Ci) processing through unknown mechanisms. Here, we show that these kinases physically interact with the kinesin-like protein Costal2 (Cos2) to control Ci processing and that Hh inhibits such interaction. Cos2 is required for Ci phosphorylation in vivo, and Cos2-immunocomplexes (Cos2IPs) phosphorylate Ci and contain PKA, GSK3, and CKI. By using a Kinesin-Cos2 chimeric protein that carries Cos2-interacting proteins to the microtubule plus end, we demonstrated that these kinases bind Cos2 in intact cells. PKA, GSK3, and CKI directly bind the N- and C-terminal regions of Cos2, both of which are essential for Ci processing. Finally, we showed that Hh signaling inhibits Cos2-kinase complex formation. We propose that Cos2 recruits multiple kinases to efficiently phosphorylate Ci and that Hh inhibits Ci phosphorylation by specifically interfering with kinase recruitment.
G protein-coupled receptor kinase 2 (Gprk2/GRK2) plays a conserved role in modulating Hedgehog (Hh) pathway activity, but its mechanism of action remains unknown. Here we provide evidence that Gprk2 promotes high-level Hh signaling by regulating Smoothened (Smo) conformation through both kinase-dependent and kinase-independent mechanisms. Gprk2 promotes Smo activation by phosphorylating Smo C-terminal tail (C-tail) at Ser741/Thr742, which is facilitated by PKA and CK1 phosphorylation at adjacent Ser residues. In addition, Gprk2 forms a dimer/oligomer and binds Smo C-tail in a kinase activity-independent manner to stabilize the active Smo conformation, and promotes dimerization/oligomerization of Smo C-tail. Gprk2 expression is induced by Hh signaling, and Gprk2/Smo interaction is facilitated by PKA/CK1-mediated phosphorylation of Smo C-tail. Thus, Gprk2 forms a positive feedback loop and acts downstream from PKA and CK1 to facilitate high-level Hh signaling by promoting the active state of Smo through direct phosphorylation and molecular scaffolding.
The three-dimensional structures of macromolecules and their complexes are predominantly elucidated by X-ray protein crystallography. A major limitation is access to high-quality crystals, to ensure X-ray diffraction extends to sufficiently large scattering angles and hence yields sufficiently high-resolution information that the crystal structure can be solved. The observation that crystals with shrunken unit-cell volumes and tighter macromolecular packing often produce higher-resolution Bragg peaks1,2 hints that crystallographic resolution for some macromolecules may be limited not by their heterogeneity but rather by a deviation of strict positional ordering of the crystalline lattice. Such displacements of molecules from the ideal lattice give rise to a continuous diffraction pattern, equal to the incoherent sum of diffraction from rigid single molecular complexes aligned along several discrete crystallographic orientations and hence with an increased information content3. Although such continuous diffraction patterns have long been observed—and are of interest as a source of information about the dynamics of proteins4 —they have not been used for structure determination. Here we show for crystals of the integral membrane protein complex photosystem II that lattice disorder increases the information content and the resolution of the diffraction pattern well beyond the 4.5 Å limit of measurable Bragg peaks, which allows us to directly phase5 the pattern. With the molecular envelope conventionally determined at 4.5 Å as a constraint, we then obtain a static image of the photosystem II dimer at 3.5 Å resolution. This result shows that continuous diffraction can be used to overcome long-supposed resolution limits of macromolecular crystallography, with a method that puts great value in commonly encountered imperfect crystals and opens up the possibility for model-free phasing6,7.
Background: 2019 novel coronavirus disease (COVID-19) has become a worldwide pandemic. Under such circumstance pregnant women are also affected significantly.Objective: This study aims to observe the clinical features and outcomes of pregnant women who have been confirmed with COVID-19. Methods: The research objects were 55 cases of suspected COVID-19 pregnant women who gave a birth from Jan 20th 2020 to Mar 5th 2020 in our hospital-a big birth center delivering about 30,0 0 0 babies in the last 3 years. These cases were subjected to pulmonary CT scan and routine blood test, manifested symptoms of fever, cough, chest tightness or gastrointestinal symptoms. They were admitted to an isolated suite, with clinical features and newborn babies being carefully observed. Among the 55 cases, 13 patients were assigned into the confirmed COVID-19 group for being tested positive sever acute respiratory syndrome coronavirus 2(SARS-CoV-2) via maternal throat swab test, and the other 42 patients were assigned into the control group for being ruled out COVID-19 pneumonia based on new coronavirus pneumonia prevention and control program(the 7th edition). Results: There were 2 fever patients during the prenatal period and 8 fever patients during the postpartum period in the confirmed COVID-19 group. In contrast, there were 11 prenatal fever patients and 20 postpartum fever patients in the control group ( p > 0.05). Among 55 cases, only 2 case had cough in the confirmed group. The imaging of pulmonary CT scan showed ground-glass opacity (46.2%, 6/13), patchlike shadows(38.5%, 5/13), fiber shadow(23.1%, 3/13), pleural effusion (38.5%, 5/13)and pleural thickening(7.7%, 1/13), and there was no statistical difference between the confirmed COVID-19 group and the control group ( p > 0.05). During the prenatal and postpartum period, there was no difference in the count of WBC, Neutrophils and Lymphocyte, the radio of Neutrophils and Lymphocyte and the level of CRP between the confirmed COVID-19 group and the control group( p < 0.05). 20 babies (from confirmed mother and from normal mother) were subjected to SARS-CoV-2 examination by throat swab samples in 24 h after birth and no case was tested positive. Conclusion:The clinical symptoms and laboratory indicators are not obvious for asymptomatic and mild COVID-19 pregnant women. Pulmonary CT scan plus blood routine examination are more suitable for finding pregnancy women with asymptomatic or mild COVID-19 infection, and can be used screening COVID-19 pregnant women in the outbreak area of COVID-19 infection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.