The protein cereblon (CRBN) is a substrate receptor of the cullin 4-really interesting new gene (RING) E3 ubiquitin ligase complex CRL4CRBN. Targeting CRBN mediates selective protein ubiquitination and subsequent degradation via the proteasome. This review describes novel thalidomide analogs, immunomodulatory drugs, also known as CRBN E3 ubiquitin ligase modulators or molecular glues (avadomide, iberdomide, CC-885, CC-90009, BTX-1188, CC-92480, CC-99282, CFT7455, and CC-91633), and CRBN-based proteolysis targeting chimeras (PROTACs) with increased efficacy and potent activity for application in hematologic malignancies. Both types of CRBN-binding drugs, molecular glues, and PROTACs stimulate the interaction between CRBN and its neosubstrates, recruiting target disease-promoting proteins and the E3 ubiquitin ligase CRL4CRBN. Proteins that are traditionally difficult to target (transcription factors and oncoproteins) can be polyubiquitinated and degraded in this way. The competition of CRBN neosubstrates with endogenous CRBN-interacting proteins and the pharmacology and rational combination therapies of and mechanisms of resistance to CRL4CRBN modulators or CRBN-based PROTACs are described.

• MeSH
• hematologické nádory * farmakoterapie   MeSH
• lidé MeSH
• proteasy * chemie   genetika   metabolismus   MeSH
• transkripční faktory metabolismus   MeSH
• ubikvitinace MeSH
• ubikvitinligasy chemie   genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

CHIP is a tetratricopeptide repeat (TPR) domain protein that functions as an E3-ubiquitin ligase. As well as linking the molecular chaperones to the ubiquitin proteasome system, CHIP also has a docking-dependent mode where it ubiquitinates native substrates, thereby regulating their steady state levels and/or function. Here we explore the effect of Hsp70 on the docking-dependent E3-ligase activity of CHIP. The TPR-domain is revealed as a binding site for allosteric modulators involved in determining CHIP's dynamic conformation and activity. Biochemical, biophysical and modeling evidence demonstrate that Hsp70-binding to the TPR, or Hsp70-mimetic mutations, regulate CHIP-mediated ubiquitination of p53 and IRF-1 through effects on U-box activity and substrate binding. HDX-MS was used to establish that conformational-inhibition-signals extended from the TPR-domain to the U-box. This underscores inter-domain allosteric regulation of CHIP by the core molecular chaperones. Defining the chaperone-associated TPR-domain of CHIP as a manager of inter-domain communication highlights the potential for scaffolding modules to regulate, as well as assemble, complexes that are fundamental to protein homeostatic control.

• MeSH
• alosterická regulace MeSH
• exprese genu MeSH
• interferonový regulační faktor 1 genetika   metabolismus   MeSH
• kinetika MeSH
• lidé MeSH
• lymfocyty cytologie   metabolismus   MeSH
• mapování interakce mezi proteiny MeSH
• molekulární modely MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• proteasomový endopeptidasový komplex metabolismus   MeSH
• proteiny tepelného šoku HSP70 chemie   genetika   metabolismus   MeSH
• sekundární struktura proteinů MeSH
• terciární struktura proteinů MeSH
• ubikvitinace MeSH
• ubikvitinligasy chemie   genetika   metabolismus   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The MAGE (Melanoma-associated antigen) protein family members are structurally related to each other by a MAGE-homology domain comprised of 2 winged helix motifs WH/A and WH/B. This family specifically evolved in placental mammals although single homologs designated NSE3 (non-SMC element) exist in most eukaryotes. NSE3, together with its partner proteins NSE1 and NSE4 form a tight subcomplex of the structural maintenance of chromosomes SMC5-6 complex. Previously, we showed that interactions of the WH/B motif of the MAGE proteins with their NSE4/EID partners are evolutionarily conserved (including the MAGEA1-NSE4 interaction). In contrast, the interaction of the WH/A motif of NSE3 with NSE1 diverged in the MAGE paralogs. We hypothesized that the MAGE paralogs acquired new RING-finger-containing partners through their evolution and form MAGE complexes reminiscent of NSE1-NSE3-NSE4 trimers. In this work, we employed the yeast 2-hybrid system to screen a human RING-finger protein library against several MAGE baits. We identified a number of potential MAGE-RING interactions and confirmed several of them (MDM4, PCGF6, RNF166, TRAF6, TRIM8, TRIM31, TRIM41) in co-immunoprecipitation experiments. Among these MAGE-RING pairs, we chose to examine MAGEA1-TRIM31 in detail and showed that both WH/A and WH/B motifs of MAGEA1 bind to the coiled-coil domain of TRIM31 and that MAGEA1 interaction stimulates TRIM31 ubiquitin-ligase activity. In addition, TRIM31 directly binds to NSE4, suggesting the existence of a TRIM31-MAGEA1-NSE4 complex reminiscent of the NSE1-NSE3-NSE4 trimer. These results suggest that MAGEA1 functions as a co-factor of TRIM31 ubiquitin-ligase and that the TRIM31-MAGEA1-NSE4 complex may have evolved from an ancestral NSE1-NSE3-NSE4 complex.

• MeSH
• biologické modely MeSH
• chromatografie kapalinová MeSH
• domény RING-prstů MeSH
• HEK293 buňky MeSH
• imunoprecipitace MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• multimerizace proteinu MeSH
• multiproteinové komplexy metabolismus   MeSH
• nádorové proteiny chemie   metabolismus   MeSH
• peptidové fragmenty chemie   metabolismus   MeSH
• peptidy chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• tandemová hmotnostní spektrometrie MeSH
• techniky dvojhybridového systému MeSH
• transportní proteiny metabolismus   MeSH
• ubikvitinligasy chemie   metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

DNA double-strand breaks (DSBs) not only interrupt the genetic information, but also disrupt the chromatin structure, and both impairments require repair mechanisms to ensure genome integrity. We showed previously that RNF8-mediated chromatin ubiquitylation protects genome integrity by promoting the accumulation of repair factors at DSBs. Here, we provide evidence that, while RNF8 is necessary to trigger the DSB-associated ubiquitylations, it is not sufficient to sustain conjugated ubiquitin in this compartment. We identified RNF168 as a novel chromatin-associated ubiquitin ligase with an ability to bind ubiquitin. We show that RNF168 interacts with ubiquitylated H2A, assembles at DSBs in an RNF8-dependent manner, and, by targeting H2A and H2AX, amplifies local concentration of lysine 63-linked ubiquitin conjugates to the threshold required for retention of 53BP1 and BRCA1. Thus, RNF168 defines a new pathway involving sequential ubiquitylations on damaged chromosomes and uncovers a functional cooperation between E3 ligases in genome maintenance.

• MeSH
• buněčné linie MeSH
• chromozomy * metabolismus   MeSH
• DNA vazebné proteiny metabolismus   MeSH
• dvouřetězcové zlomy DNA * MeSH
• genový knockdown MeSH
• histony metabolismus   MeSH
• intracelulární signální peptidy a proteiny metabolismus   MeSH
• lidé MeSH
• oprava DNA * MeSH
• terciární struktura proteinů MeSH
• ubikvitin * metabolismus   MeSH
• ubikvitinligasy * chemie   genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH