1
|
Horn-Ghetko D, Hopf LVM, Tripathi-Giesgen I, Du J, Kostrhon S, Vu DT, Beier V, Steigenberger B, Prabu JR, Stier L, Bruss EM, Mann M, Xiong Y, Schulman BA. Noncanonical assembly, neddylation and chimeric cullin-RING/RBR ubiquitylation by the 1.8 MDa CUL9 E3 ligase complex. Nat Struct Mol Biol 2024; 31:1083-1094. [PMID: 38605244 PMCID: PMC11257990 DOI: 10.1038/s41594-024-01257-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 02/26/2024] [Indexed: 04/13/2024]
Abstract
Ubiquitin ligation is typically executed by hallmark E3 catalytic domains. Two such domains, 'cullin-RING' and 'RBR', are individually found in several hundred human E3 ligases, and collaborate with E2 enzymes to catalyze ubiquitylation. However, the vertebrate-specific CUL9 complex with RBX1 (also called ROC1), of interest due to its tumor suppressive interaction with TP53, uniquely encompasses both cullin-RING and RBR domains. Here, cryo-EM, biochemistry and cellular assays elucidate a 1.8-MDa hexameric human CUL9-RBX1 assembly. Within one dimeric subcomplex, an E2-bound RBR domain is activated by neddylation of its own cullin domain and positioning from the adjacent CUL9-RBX1 in trans. Our data show CUL9 as unique among RBX1-bound cullins in dependence on the metazoan-specific UBE2F neddylation enzyme, while the RBR domain protects it from deneddylation. Substrates are recruited to various upstream domains, while ubiquitylation relies on both CUL9's neddylated cullin and RBR domains achieving self-assembled and chimeric cullin-RING/RBR E3 ligase activity.
Collapse
|
2
|
Botsch JJ, Junker R, Sorgenfrei M, Ogger PP, Stier L, von Gronau S, Murray PJ, Seeger MA, Schulman BA, Bräuning B. Doa10/MARCH6 architecture interconnects E3 ligase activity with lipid-binding transmembrane channel to regulate SQLE. Nat Commun 2024; 15:410. [PMID: 38195637 PMCID: PMC10776854 DOI: 10.1038/s41467-023-44670-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 12/19/2023] [Indexed: 01/11/2024] Open
Abstract
Transmembrane E3 ligases play crucial roles in homeostasis. Much protein and organelle quality control, and metabolic regulation, are determined by ER-resident MARCH6 E3 ligases, including Doa10 in yeast. Here, we present Doa10/MARCH6 structural analysis by cryo-EM and AlphaFold predictions, and a structure-based mutagenesis campaign. The majority of Doa10/MARCH6 adopts a unique circular structure within the membrane. This channel is established by a lipid-binding scaffold, and gated by a flexible helical bundle. The ubiquitylation active site is positioned over the channel by connections between the cytosolic E3 ligase RING domain and the membrane-spanning scaffold and gate. Here, by assaying 95 MARCH6 variants for effects on stability of the well-characterized substrate SQLE, which regulates cholesterol levels, we reveal crucial roles of the gated channel and RING domain consistent with AlphaFold-models of substrate-engaged and ubiquitylation complexes. SQLE degradation further depends on connections between the channel and RING domain, and lipid binding sites, revealing how interconnected Doa10/MARCH6 elements could orchestrate metabolic signals, substrate binding, and E3 ligase activity.
Collapse
|
3
|
Fiore A, Zeitler L, Russier M, Groß A, Hiller MK, Parker JL, Stier L, Köcher T, Newstead S, Murray PJ. Kynurenine importation by SLC7A11 propagates anti-ferroptotic signaling. Mol Cell 2022; 82:920-932.e7. [PMID: 35245456 DOI: 10.1016/j.molcel.2022.02.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 11/17/2021] [Accepted: 02/02/2022] [Indexed: 12/19/2022]
Abstract
IDO1 oxidizes tryptophan (TRP) to generate kynurenine (KYN), the substrate for 1-carbon and NAD metabolism, and is implicated in pro-cancer pathophysiology and infection biology. However, the mechanistic relationships between IDO1 in amino acid depletion versus product generation have remained a longstanding mystery. We found an unrecognized link between IDO1 and cell survival mediated by KYN that serves as the source for molecules that inhibit ferroptotic cell death. We show that this effect requires KYN export from IDO1-expressing cells, which is then available for non-IDO1-expressing cells via SLC7A11, the central transporter involved in ferroptosis suppression. Whether inside the "producer" IDO1+ cell or the "receiver" cell, KYN is converted into downstream metabolites, suppressing ferroptosis by ROS scavenging and activating an NRF2-dependent, AHR-independent cell-protective pathway, including SLC7A11, propagating anti-ferroptotic signaling. IDO1, therefore, controls a multi-pronged protection pathway from ferroptotic cell death, underscoring the need to re-evaluate the use of IDO1 inhibitors in cancer treatment.
Collapse
|
4
|
Dlugacz YD, Stier L, Greenwood A. Changing the system: a quality management approach to pressure injuries. J Healthc Qual 2001; 23:15-9; quiz 19-20. [PMID: 11565165 DOI: 10.1111/j.1945-1474.2001.tb00369.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The quality management (QM) department at a large integrated healthcare system developed a methodology for preventing, predicting, and treating pressure injuries across the continuum, from acute care to long-term care to home care. The initiative, the first recipient of the Ernest A. Codman Award of the Joint Commission on Accreditation of Healthcare Organizations in the network category, resulted in decreased incidence and severity of pressure injuries, reduced length of stay, and significant cost savings to the system. The process the department used illustrates how an innovative QM program can facilitate change and institute a uniform standard of care.
Collapse
|
5
|
Siegfried W, Rosenfeld M, Stier L, Stratford-Perricaudet L, Perricaudet M, Pavirani A, Lecocq JP, Crystal RG. Polarity of secretion of alpha 1-antitrypsin by human respiratory epithelial cells after adenoviral transfer of a human alpha 1-antitrypsin cDNA. Am J Respir Cell Mol Biol 1995; 12:379-84. [PMID: 7695917 DOI: 10.1165/ajrcmb.12.4.7695917] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
alpha 1-Antitrypsin (alpha AT) deficiency, a hereditary cause of progressive emphysema, can potentially be treated by transfer of a functional human alpha 1AT gene to the respiratory epithelium. For such an approach to be successful, alpha 1AT must be provided to both the interstitium and the epithelial surface--that is, the alpha 1AT directed by the transferred gene must be secreted to both the apical and basolateral surfaces of the epithelial cells. To evaluate this concept, a recombinant, replication-deficient adenoviral vector (Ad-alpha 1AT) containing a human alpha 1AT cDNA driven by an adenovirus major late promoter was used to infect Bet-1A human respiratory epithelial cells. The infected cells expressed Ad-alpha 1AT-directed mRNA transcripts and synthesized and secreted functional human alpha 1AT as shown by [35S]methionine labeling and immunoprecipitation of a 52-kD glycosylated human alpha 1AT molecule capable of interacting with neutrophil elastase, its natural substrate. Bet-1A cells grown on microporous polycarbonate membranes formed tight junctions (resistance > 150 omega x cm2). After infection with Ad-alpha 1AT, [35S]methionine labeling and enzyme-linked immunoassay demonstrated that alpha 1AT was secreted into both the apical and basolateral compartments, with an average apical to basolateral ratio of 1.9 +/- 0.2. Thus, human respiratory epithelial cells infected with a recombinant adenoviral vector containing a human alpha 1AT cDNA secrete alpha 1AT across both the apical and basolateral cell membranes, suggesting that the respiratory epithelium could serve as a target for in vivo gene therapy of alpha 1AT deficiency.
Collapse
|
6
|
Curiel D, Brantly M, Curiel E, Stier L, Crystal RG. Alpha 1-antitrypsin deficiency caused by the alpha 1-antitrypsin Nullmattawa gene. An insertion mutation rendering the alpha 1-antitrypsin gene incapable of producing alpha 1-antitrypsin. J Clin Invest 1989; 83:1144-52. [PMID: 2539391 PMCID: PMC303800 DOI: 10.1172/jci113994] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
alpha 1-Antitrypsin (alpha 1AT) deficiency is a hereditary disorder associated with reduced serum alpha 1AT levels and the development of pulmonary emphysema. An alpha 1AT gene is defined as "Null" when no alpha 1AT in serum is attributed to that alpha 1AT gene. Although all alpha 1AT Null genes have identical phenotypic consequences (i.e. no detectable alpha 1AT in the serum), different genotypic mechanisms can cause the Null state. This study defines the molecular basis for the alpha 1AT gene Nullmattawa, identified and cloned from genomic DNA of an individual with the Null-Null phenotype and emphysema resulting from the heterozygous inheritance of the Nullmattawa and Nullbellingham genes. Sequencing of exons Ic-V and all exon-intron junctions of the Nullmattawa gene demonstrated it was identical to the common normal M1(Val213) alpha 1AT gene except for the insertion of a single nucleotide within the coding region of exon V, causing a 3' frameshift with generation of a premature stop signal. Family analysis using oligonucleotide probes specific for the Nullmattawa sequence demonstrated the gene was inherited in an autosomal fashion. Examination of blood monocytes demonstrated that a normal-sized, 1.8-kb alpha 1AT mRNA transcript is associated with the Nullmattawa gene and in vitro translation of mRNA with the Nullmattawa mutation showed it translated at a normal rate but produced a truncated alpha 1AT protein. Additionally, retroviral transfer of the alpha 1AT Nullmattawa cDNA to murine fibroblasts demonstrated no detectable intracellular or secreted alpha 1AT, despite the presence of alpha 1AT Nullmattawa mRNA transcripts. These findings are consistent with the concept that the molecular pathophysiology of Nullmattawa is likely manifested at a posttranslational level. The identification of the Nullmattawa gene supports the concept that Null alpha 1AT alleles represent a heterogenous group in which very different mechanisms cause the identical phenotypic state.
Collapse
|
7
|
Takahashi H, Nukiwa T, Satoh K, Ogushi F, Brantly M, Fells G, Stier L, Courtney M, Crystal RG. Characterization of the gene and protein of the alpha 1-antitrypsin "deficiency" allele Mprocida. J Biol Chem 1988; 263:15528-34. [PMID: 3262617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The "deficiency" group of alpha 1-antitrypsin (alpha 1AT) alleles is characterized by alpha 1AT genes that code for alpha 1AT present in serum but in amounts insufficient to protect the lower respiratory tract from progressive destruction by its burden of neutrophil elastase. Mprocida, a rare alpha 1AT allele associated with alpha 1AT serum levels less than 10 mg/dl (normal 150-350 mg/dl), codes for an alpha 1AT molecule that focuses on immobilized pH gradient isoelectric gels slightly cathodal to the common normal M1 (Val213) protein. On a per molecule basis, Mprocida has a mildly reduced function as an inhibitor, with an association rate constant for human neutrophil elastase of 7.0 +/- 0.1 x 10(6) M-1 s-1 (normal M1 (Val213) 9.3 +/- 0.8 x 10(6), p less than 0.01). The Mprocida molecule behaves normally in vivo with a half-life similar to normal M1 alpha 1AT molecules. Restriction endonuclease mapping demonstrates that the cloned Mprocida gene was grossly intact. Sequencing of all the exons, exon-intron junctions, and the major promoter region demonstrated Mprocida to be identical to the M1 (Val213) gene except for a single base substitution in exon II coding for amino acid 41 of the mature protein (M1 (Val213) Leu41 CTG----Mprocida Pro41 CCG). Usefully, the coding sequence of the alpha 1AT residues 40-41 is recognized by the restriction endonuclease PvuII so that using a probe corresponding to this region of exon II, the Mprocida mutation can be rapidly identified by Southern analysis. Evaluation of the crystallographic structure of alpha 1AT suggests the Leu41 to Pro41 mutation may disrupt alpha-helix A in the region of Pro21-Ser45, suggesting the possibility that the alpha 1AT Mprocida molecule is unstable and degraded intracellularly prior to secretion.
Collapse
|
8
|
Takahashi H, Nukiwa T, Satoh K, Ogushi F, Brantly M, Fells G, Stier L, Courtney M, Crystal RG. Characterization of the gene and protein of the alpha 1-antitrypsin "deficiency" allele Mprocida. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(19)37620-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
9
|
Nukiwa T, Brantly M, Ogushi F, Fells G, Satoh K, Stier L, Courtney M, Crystal RG. Characterization of the M1(Ala213) type of alpha 1-antitrypsin, a newly recognized, common "normal" alpha 1-antitrypsin haplotype. Biochemistry 1987; 26:5259-67. [PMID: 2890373 DOI: 10.1021/bi00391a008] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
alpha 1-Antitrypsin (alpha 1AT) is a highly pleomorphic 52-kDa serum glycoprotein that functions as the major inhibitor of neutrophil elastase. Of these, the most common normal alpha 1AT haplotypes identified by isoelectric focusing (IEF) of serum are those of the M family, including M1, M2, and M3. In the course of studying the alpha 1AT type Z gene, we identified a restriction endonuclease BstEII polymorphism in the M1 gene that predicted the existence of a previously unidentified, but relatively common, haplotype of M, referred to as M1(Ala213) [Nukiwa, T., Satoh, K., Brantly, M. L., Ogushi, F., Fells, G. A., Courtney, M., & Crystal, R. G. (1986) J. Biol. Chem. 261, 15989-15994]. In this study we have cloned both alpha 1AT genes from an individual heterozygous for the M1(Ala213) and M1(Val213) haplotypes. Sequencing of the coding exons of both demonstrated that they are identical except for the Ala-Val difference at residue 213. The codominant transmission of the M1(Ala213) gene was demonstrated in a family study. Evaluation of 39 genomic samples of Caucasians with the IEF haplotype M1 demonstrated haplotype frequencies of 68% for M1(Val213) and 32% for M1(Ala213). alpha 1AT serum levels of individuals inheriting the M1(Ala213) gene in a homozygous fashion were in the same range as those for homozygous M1(Val213) as was the rate of association of the M1(Ala213) protein with neutrophil elastase.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
10
|
Rennard SI, Moss J, Oberpriller J, Hom B, Stier L, Ozaki T, Crystal RG. Fibroblasts: important producers and targets of inflammatory prostaglandins in the lungs. Chest 1983; 83:92S-93S. [PMID: 6573248 DOI: 10.1378/chest.83.5_supplement.92s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
|
11
|
Rennard SI, Moss J, Oberpriller J, Hom B, Stier L, Ozaki T, Crystal RG. Fibroblasts: important producers and targets of inflammatory prostaglandins in the lungs. Chest 1983. [DOI: 10.1378/chest.83.5.92s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
|