Refine
Year of publication
Has Fulltext
- yes (70)
Is part of the Bibliography
- no (70)
Keywords
- autophagy (8)
- glioblastoma (5)
- apoptosis (3)
- cell biology (3)
- phosphorylation (3)
- ubiquitin (3)
- ubiquitination (3)
- Autophagy (2)
- BAG3 (2)
- Biochemistry (2)
- Cell biology (2)
- USP28 (2)
- Ubiquitylation (2)
- aging (2)
- c-MYC (2)
- cell death (2)
- cell migration (2)
- epithelial to mesenchymal transition (2)
- human (2)
- inflammation (2)
- lung cancer (2)
- mouse (2)
- oligomerisation (2)
- primary cilium (2)
- receptor (2)
- triple-negative breast cancer (2)
- 3Cs technology (1)
- AML – acute myeloid leukemia (1)
- AMPK (1)
- ATG4 (1)
- ATG8 (1)
- BRAF (1)
- BRD4 (1)
- BRD4-NUT (1)
- Bag6 (1)
- Buparlisib (1)
- C. elegans (1)
- Calnexin (1)
- Cancer (1)
- Conventional and unconventional ubiquitination (1)
- Crispr/Cas (1)
- DNA damage (1)
- DNA replication (1)
- DNA-protein crosslinks (1)
- DUBs (1)
- Doxorubicin (1)
- Dvc1 (1)
- E. coli (1)
- EGFR (1)
- Endoplasmic reticulum (1)
- FAM134B (1)
- Feasibility (1)
- G9a/EHMT2/KMT1C (1)
- HRAS 28 Gefitinib (1)
- Hedgehog (1)
- Immunology (1)
- KCGS (1)
- LAMTOR1 (1)
- LC3/GABARAP (1)
- LC3B (1)
- LIR (1)
- LIR interaction, (1)
- LPS (1)
- LUBAC (1)
- Legionella pneumophila (1)
- Manatee invariant (1)
- Mathematical model (1)
- Microbiology (1)
- Mislocalised proteins (1)
- Mitophagy (1)
- NF-κB (1)
- NF-κB pathway (1)
- Notch (1)
- PIK3CA (1)
- Pathogens (1)
- Petri net (1)
- Phosphorylation (1)
- Proteasomes (1)
- Protein Structure (1)
- Protein degradation (1)
- Protein-Protein Interactions (1)
- ROS (1)
- RUFY (1)
- Rab7 (1)
- Ragulator complex (1)
- Research article (1)
- Reticulon (1)
- Rtn3 (1)
- Ruijs-Aalfs syndrome (1)
- S. cerevisiae (1)
- SARS-CoV-2 (1)
- SIRT1 (1)
- SPARTAN (1)
- SPRTN (1)
- Selective autophagy (1)
- Sharpin (1)
- Signal Transduction (1)
- Signaling pathway (1)
- Skp (1)
- TAX1BP1 (1)
- TBK1 (1)
- TNFR1 (1)
- TPR (1)
- Tools and ressources (1)
- Topoisomerase (1)
- Transition invariant (1)
- UBA5 (1)
- UFIM (1)
- UFM1 (1)
- USP32 (1)
- Ubiquitin Ligase (1)
- Ubiquitin signaling (1)
- Ubiquitin-binding module (1)
- Ubiquitination (1)
- Vemurafenib (1)
- WRNIP1 (1)
- X-ray Crystallography (1)
- alveolar macrophages (1)
- antiviral signaling (1)
- astrocytoma (1)
- bacteria (1)
- biochemistry (1)
- buparlisib (1)
- c-JUN (1)
- c1orf124 (1)
- calcitriol (1)
- cancer (1)
- cancer stem cells (1)
- chemogenomic set (1)
- collagen (1)
- cytarabin (1)
- deubiquitinase (DUB) (1)
- differentiation (1)
- drug discovery (1)
- druggable genome (1)
- endoplasmic reticulum (1)
- famotidine (1)
- fasting (1)
- gRNA library (1)
- gefitinib (1)
- genetics and genomics (1)
- genome-wide (1)
- glioblastoma stem-like cells (1)
- green fluorescent protein (1)
- hMOF/KAT8 (1)
- histamine (1)
- immunology (1)
- inhibitors (1)
- innate immunity (1)
- isothermal titration calorimetry (ITC) (1)
- kinase inhibitor (1)
- life span (1)
- lysosomes (1)
- mTORC1 (1)
- metabolic syndromes (1)
- metabolism (1)
- metalloprotease (1)
- mitochondrial metabolism (1)
- mitochondrial morphology (1)
- mitophagy (1)
- neurodegeneration (1)
- novel technologies (1)
- nuclear hormone receptor (1)
- nuclear magnetic resonance (NMR) (1)
- phage display (1)
- phenotypic screening (1)
- pol g (1)
- progeria (1)
- protein kinase (1)
- protein motif (1)
- selective autophagy (1)
- selective autophagy receptor (1)
- short linear motifs (SLiMs) (1)
- signal transduction (1)
- skin inflammation (1)
- small molecules (1)
- stress response (1)
- teratoma (1)
- toll-like receptor (1)
- transcriptional regulation of autophagy (1)
- ubiquitin-binding zinc finger (1)
- understudied kinase (1)
- v-ATPase (1)
- vemurafenib (1)
- viruses (1)
- vitamin D3 (1)
- x-ray crystallography (1)
Institute
- Medizin (59)
- Buchmann Institut für Molekulare Lebenswissenschaften (BMLS) (18)
- Exzellenzcluster Makromolekulare Komplexe (14)
- Biochemie und Chemie (11)
- Biochemie, Chemie und Pharmazie (5)
- Biowissenschaften (4)
- MPI für Biophysik (4)
- Physik (3)
- Informatik (2)
- Biodiversität und Klima Forschungszentrum (BiK-F) (1)
- Georg-Speyer-Haus (1)
- Präsidium (1)
- Senckenbergische Naturforschende Gesellschaft (1)
- Zentrum für Biomolekulare Magnetische Resonanz (BMRZ) (1)
Reversible phosphorylation plays important roles in G protein-coupled receptor signaling, desensitization, and endocytosis, yet the precise location and role of in vivo phosphorylation sites is unknown for most receptors. Using metabolic 32P labeling and phosphopeptide sequencing we provide a complete phosphorylation map of the human bradykinin B2 receptor in its native cellular environment. We identified three serine residues, Ser(339), Ser(346), and Ser(348), at the C-terminal tail as principal phosphorylation sites. Constitutive phosphorylation occurs at Ser(348), while ligand-induced phosphorylation is found at Ser(339) and Ser(346)/Ser(348) that could be executed by several G protein-coupled receptor kinases. In addition, we found a protein kinase C-dependent phosphorylation of Ser(346) that was mutually exclusive with the basal phosphorylation at Ser(348) and therefore may be implicated in differential regulation of B2 receptor activation. Functional analysis of receptor mutants revealed that a low phosphorylation stoichiometry is sufficient to initiate receptor sequestration while a clustered phosphorylation around Ser(346) is necessary for desensitization of the B2 receptor-induced phospholipase C activation. This was further supported by the specifically reduced Ser(346)/Ser(348) phosphorylation observed upon stimulation with a nondesensitizing B2 receptor agonist. The differential usage of clustered phosphoacceptor sites points to distinct roles of multiple kinases in controlling G protein-coupled receptor function.
In PC12 cells, a well studied model for neuronal differentiation, an elevation in the intracellular cAMP level increases cell survival, stimulates neurite outgrowth, and causes activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2). Here we show that an increase in the intracellular cAMP concentration induces tyrosine phosphorylation of two receptor tyrosine kinases, i.e. the epidermal growth factor (EGF) receptor and the high affinity receptor for nerve growth factor (NGF), also termed Trk(A). cAMP-induced tyrosine phosphorylation of the EGF receptor is rapid and correlates with ERK1/2 activation. It occurs also in Panc-1, but not in human mesangial cells. cAMP-induced tyrosine phosphorylation of the NGF receptor is slower and correlates with Akt activation. Inhibition of EGF receptor tyrosine phosphorylation, but not of the NGF receptor, reduces cAMP-induced neurite outgrowth. Expression of dominant-negative Akt does not abolish cAMP-induced survival in serum-free media, but increases cAMP-induced ERK1/2 activation and neurite outgrowth. Together, our results demonstrate that cAMP induces dual signaling in PC12 cells: transactivation of the EGF receptor triggering the ERK1/2 pathway and neurite outgrowth; and transactivation of the NGF receptor promoting Akt activation and thereby modulating ERK1/2 activation and neurite outgrowth.
Erratum in: Correction: Cyclic AMP induces transactivation of the receptors for epidermal growth factor and nerve growth factor, thereby modulating activation of MAP kinase, Akt, and neurite outgrowth in PC12 cells. Journal of biological chemistry 2020 Oct 23;295(43):14792. doi: 10.1074/jbc.AAC120.016177.
Alix/AIP1 is an adaptor protein involved in regulating the function of receptor and cytoskeleton-associated tyrosine kinases. Here, we investigated its interaction with and regulation by Src. Tyr319 of Alix bound the isolated Src homology-2 (SH2) domain and was necessary for interaction with intact Src. A proline-rich region in the C terminus of Alix bound the Src SH3 domain, but this interaction was dependent on the release of the Src SH2 domain from its Src internal ligand either by interaction with Alix Tyr319 or by mutation of Src Tyr527. Src phosphorylated Alix at a C-terminal region rich in tyrosines, an activity that was stimulated by the presence of the Alix binding partner SETA/CIN85. Phosphorylation of Alix by Src caused it to translocate from the membrane and cytoskeleton to the cytoplasm and reduced its interaction with binding partners SETA/CIN85, epidermal growth factor receptor, and Pyk2. As a consequence of this, Src antagonized the negative regulation of receptor tyrosine kinase internalization and cell adhesion by Alix. We propose a model whereby Src antagonizes the effects of Alix by phosphorylation of its C terminus, leading to the disruption of interactions with target proteins.
The ubiquitin (Ub) ligase Cbl plays a critical role in attenuation of receptor tyrosine kinase (RTK) signaling by inducing ubiquitination of RTKs and promoting their sorting for endosomal degradation. Herein, we describe the identification of two novel Cbl-interacting proteins, p70 and Clip4 (recently assigned the names Sts-1 and Sts-2, respectively), that inhibit endocytosis of epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor. Sts-1 and Sts-2 contain SH3 domains that interacted with Cbl, Ub-associated domains, which bound directly to mono-Ub or to the EGFR/Ub chimera as well as phosphoglycerate mutase domains that mediated oligomerization of Sts-1/2. Ligand-induced recruitment of Sts-1/Sts-2 into activated EGFR complexes led to inhibition of receptor internalization, reduction in the number of EGFR-containing endocytic vesicles, and subsequent block of receptor degradation followed by prolonged activation of mitogenic signaling pathways. On the other hand, interference with Sts-1/Sts-2 functions diminished ligand-induced receptor degradation, cell proliferation, and oncogenic transformation in cultured fibroblasts. We suggest that Sts-1 and Sts-2 represent a novel class of Ub-binding proteins that regulate RTK endocytosis and control growth factor-induced cellular functions.
SUMO proteins are ubiquitin-related modifiers implicated in the regulation of gene transcription, cell cycle, DNA repair, and protein localization. The molecular mechanisms by which the sumoylation of target proteins regulates diverse cellular functions remain poorly understood. Here we report isolation and characterization of SUMO1- and SUMO2-binding motifs. Using yeast two-hybrid system, bioinformatics, and NMR spectroscopy we define a common SUMO-interacting motif (SIM) and map its binding surfaces on SUMO1 and SUMO2. This motif forms a beta-strand that could bind in parallel or antiparallel orientation to the beta2-strand of SUMO due to the environment of the hydrophobic core. A negative charge imposed by a stretch of neighboring acidic amino acids and/or phosphorylated serine residues determines its specificity in binding to distinct SUMO paralogues and can modulate the spatial orientation of SUMO-SIM interactions.
Defects in podocyte signaling are the basis of many inherited glomerular diseases leading to glomerulosclerosis. CD2-associated protein (CD2AP) is highly expressed in podocytes and is considered to play an important role in the maintenance of the glomerular slit diaphragm. Mice deficient for CD2AP (CD2AP(-/-)) appear normal at birth but develop a rapid onset nephrotic syndrome at 3 weeks of age. We demonstrate that impaired intracellular signaling with subsequent podocyte damage is the reason for this delayed podocyte injury in CD2AP(-/-) mice. We document that CD2AP deficiency in podocytes leads to diminished signal initiation and termination of signaling pathways mediated by receptor tyrosine kinases (RTKs). In addition, we demonstrate that CIN85, a paralog of CD2AP, is involved in termination of RTK signaling in podocytes. CIN85 protein expression is increased in CD2AP(-/-) podocytes in vitro. Stimulation of CD2AP(-/-) podocytes with various growth factors, including insulin-like growth factor 1, vascular endothelial growth factor, and fibroblast growth factor, resulted in a significantly decreased phosphatidylinositol 3-kinase/AKT and ERK signaling response. Moreover, increased CIN85 protein is detectable in podocytes in diseased CD2AP(-/-) mice, leading to decreased base-line activation of ERK and decreased phosphorylation after growth factor stimulation in vivo. Because repression of CIN85 protein leads to a restored RTK signaling response, our results support an important role of CD2AP/CIN85 protein balance in the normal signaling response of podocytes.
Bypassing of DNA lesions by damage-tolerant DNA polymerases depends on the interaction of these enzymes with the monoubiquitylated form of the replicative clamp protein, PCNA. We have analyzed the contributions of ubiquitin and PCNA binding to damage bypass and damage-induced mutagenesis in Polymerase {eta} (encoded by RAD30) from the budding yeast Saccharomyces cerevisiae. We report here that a ubiquitin-binding domain provides enhanced affinity for the ubiquitylated form of PCNA and is essential for in vivo function of the polymerase, but only in conjunction with a basal affinity for the unmodified clamp, mediated by a conserved PCNA interaction motif. We show that enhancement of the interaction and function in damage tolerance does not depend on the ubiquitin attachment site within PCNA. Like its mammalian homolog, budding yeast Polymerase {eta} itself is ubiquitylated in a manner dependent on its ubiquitin-binding domain.
Background The EGF receptor has been shown to internalize via clathrin-independent endocytosis (CIE) in a ligand concentration dependent manner. From a modeling point of view, this resembles an ultrasensitive response, which is the ability of signaling networks to suppress a response for low input values and to increase to a pre-defined level for inputs exceeding a certain threshold. Several mechanisms to generate this behaviour have been described theoretically, the underlying assumptions of which, however, have not been experimentally demonstrated for the EGF receptor internalization network. Results Here, we present a mathematical model of receptor sorting into alternative pathways that explains the EGF-concentration dependent response of CIE. The described mechanism involves a saturation effect of the dominant clathrin-dependent endocytosis pathway and implies distinct steady-states into which the system is forced for low vs high EGF stimulations. The model is minimal since no experimentally unjustified reactions or parameter assumptions are imposed. We demonstrate the robustness of the sorting effect for large parameter variations and give an analytic derivation for alternative steady-states that are reached. Further, we describe extensibility of the model to more than two pathways which might play a role in contexts other than receptor internalization. Conclusions Our main result is that a scenario where different endocytosis routes consume the same form of receptor corroborates the observation of a clear-cut, stimulus dependent sorting. This is especially important since a receptor modification discriminating between the pathways has not been found. The model is not restricted to EGF receptor internalization and might account for ultrasensitivity in other cellular contexts.
Requirements for the interaction of mouse Polkappa with ubiquitin and its biological significance
(2008)
Polkappa protein is a eukaryotic member of the DinB/Polkappa branch of the Y-family DNA polymerases, which are involved in the tolerance of DNA damage by replicative bypass. Despite universal conservation through evolution, the precise role(s) of Polkappa in this process has remained unknown. Here we report that mouse Polkappa can physically interact with ubiquitin by yeast two-hybrid screening, glutathione S-transferase pulldown, and immunoprecipitation methods. The association of Polkappa with ubiquitin requires the ubiquitin-binding motifs located at the C terminus of Polkappa. In addition, Polkappa binds with monoubiquitinated proliferating cell nuclear antigen (PCNA) more robustly than with non-ubiquitinated PCNA. The ubiquitin-binding motifs mediate the enhanced association between monoubiquitinated PCNA and Polkappa. The ubiquitin-binding motifs are also required for Polkappa to form nuclear foci after UV radiation. However, the ubiquitin-binding motifs do not affect Polkappa half-life. Finally, we have examined levels of Polkappa expression following the exposure of mouse cells to benzo[a]pyrene-dihydrodiol epoxide or UVB radiation.