1
|
Lei Y, Zhang X, Xu Q, Liu S, Li C, Jiang H, Lin H, Kong E, Liu J, Qi S, Li H, Xu W, Lu K. Autophagic elimination of ribosomes during spermiogenesis provides energy for flagellar motility. Dev Cell 2021; 56:2313-2328.e7. [PMID: 34428398 DOI: 10.1016/j.devcel.2021.07.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 05/17/2021] [Accepted: 07/23/2021] [Indexed: 02/05/2023]
Abstract
How autophagy initiation is regulated and what the functional significance of this regulation is are unknown. Here, we characterized the role of yeast Vac8 in autophagy initiation through recruitment of PIK3C3-C1 to the phagophore assembly site (PAS). This recruitment is dependent on the palmitoylation of Vac8 and on its middle ARM domains for binding PIK3C3-C1. Vac8-mediated anchoring of PIK3C3-C1 promotes PtdIns3P generation at the PAS and recruitment of the PtdIns3P binding protein Atg18-Atg2. The mouse homolog of Vac8, ARMC3, is conserved and functions in autophagy in mouse testes. Mice lacking ARMC3 have normal viability but show complete male infertility. Proteomic analysis indicated that the autophagic degradation of cytosolic ribosomes was blocked in ARMC3-deficient spermatids, which caused low energy levels of mitochondria and motionless flagella. These studies uncovered a function of Vac8/ARMC3 in PtdIns3-kinase anchoring at the PAS and its physical significance in mammalian spermatogenesis with a germ tissue-specific autophagic function.
Collapse
Affiliation(s)
- Yuqing Lei
- Department of Pathology, West China Second University Hospital, State Key Laboratory of Biotherapy, and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, Sichuan University, Chengdu 610041, China
| | - Xueguang Zhang
- Department of Obstetrics/Gynecology, Joint Laboratory of Reproductive Medicine (SCU-CUHK), Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu 610041, China
| | - Qingjia Xu
- Department of Neurology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shiyan Liu
- Department of Neurology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chunxia Li
- Department of Neurology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Hui Jiang
- Department of Urology, Peking University Third Hospital, Beijing 100191, China; Department of Reproductive Medicine Center, Peking University Third Hospital, Beijing 100191, China
| | - Haocheng Lin
- Department of Urology, Peking University Third Hospital, Beijing 100191, China; Department of Reproductive Medicine Center, Peking University Third Hospital, Beijing 100191, China
| | - Eryan Kong
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang 453003, China
| | - Jiaming Liu
- Department of Urology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shiqian Qi
- Department of Urology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Huihui Li
- Department of Pathology, West China Second University Hospital, State Key Laboratory of Biotherapy, and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, Sichuan University, Chengdu 610041, China.
| | - Wenming Xu
- Department of Obstetrics/Gynecology, Joint Laboratory of Reproductive Medicine (SCU-CUHK), Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu 610041, China.
| | - Kefeng Lu
- Department of Neurology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.
| |
Collapse
|
2
|
Hemsley PA, Weimar T, Lilley KS, Dupree P, Grierson CS. A proteomic approach identifies many novel palmitoylated proteins in Arabidopsis. THE NEW PHYTOLOGIST 2013; 197:805-814. [PMID: 23252521 DOI: 10.1111/nph.12077] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 10/31/2012] [Indexed: 05/06/2023]
Abstract
S-acylation (palmitoylation) is a poorly understood post-translational modification of proteins involving the addition of acyl lipids to cysteine residues. S-acylation promotes the association of proteins with membranes and influences protein stability, microdomain partitioning, membrane targeting and activation state. No consensus motif for S-acylation exists and it therefore requires empirical identification. Here, we describe a biotin switch isobaric tagging for relative and absolute quantification (iTRAQ)-based method to identify S-acylated proteins from Arabidopsis. We use these data to predict and confirm S-acylation of proteins not in our dataset. We identified c. 600 putative S-acylated proteins affecting diverse cellular processes. These included proteins involved in pathogen perception and response, mitogen-activated protein kinases (MAPKs), leucine-rich repeat receptor-like kinases (LRR-RLKs) and RLK superfamily members, integral membrane transporters, ATPases, soluble N-ethylmaleimide-sensitive factor-activating protein receptors (SNAREs) and heterotrimeric G-proteins. The prediction of S-acylation of related proteins was demonstrated by the identification and confirmation of S-acylation sites within the SNARE and LRR-RLK families. We showed that S-acylation of the LRR-RLK FLS2 is required for a full response to elicitation by the flagellin derived peptide flg22, but is not required for localization to the plasma membrane. Arabidopsis contains many more S-acylated proteins than previously thought. These data can be used to identify S-acylation sites in related proteins. We also demonstrated that S-acylation is required for full LRR-RLK function.
Collapse
Affiliation(s)
- Piers A Hemsley
- School of Biological Science, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK
| | - Thilo Weimar
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Kathryn S Lilley
- Cambridge Centre for Proteomics, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
| | - Paul Dupree
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Claire S Grierson
- School of Biological Science, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK
| |
Collapse
|
3
|
Zeng Q, Wang X, Running MP. Dual lipid modification of Arabidopsis Ggamma-subunits is required for efficient plasma membrane targeting. PLANT PHYSIOLOGY 2007; 143:1119-31. [PMID: 17220359 PMCID: PMC1820929 DOI: 10.1104/pp.106.093583] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Posttranslational lipid modifications are important for proper localization of many proteins in eukaryotic cells. However, the functional interrelationships between lipid modification processes in plants remain unclear. Here we demonstrate that the two heterotrimeric G-protein gamma-subunits from Arabidopsis (Arabidopsis thaliana), AGG1 and AGG2, are prenylated, and AGG2 is S-acylated. In wild type, enhanced yellow fluorescent protein-fused AGG1 and AGG2 are associated with plasma membranes, with AGG1 associated with internal membranes as well. Both can be prenylated by either protein geranylgeranyltransferase I (PGGT-I) or protein farnesyltransferase (PFT). Their membrane localization is intact in mutants lacking PFT activity and largely intact in mutants lacking PGGT-I activity but is disrupted in mutants lacking both PFT and PGGT-I activity. Unlike in mammals, Arabidopsis Ggammas do not rely on functional Galpha for membrane targeting. Mutation of the sixth to last cysteine, the putative S-acylation acceptor site, causes a dramatic change in AGG2 but not AGG1 localization pattern, suggesting S-acylation serves as an important additional signal for AGG2 to be targeted to the plasma membrane. Domain-swapping experiments suggest that a short charged sequence at the AGG2 C terminus contributes to AGG2's efficient membrane targeting compared to AGG1. Our data show the large degree to which PFT and PGGT-I can compensate for each other in plants and suggest that differential lipid modification plays an important regulatory role in plant protein localization.
Collapse
Affiliation(s)
- Qin Zeng
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
| | | | | |
Collapse
|
4
|
Thorp EB, Boscarino JA, Logan HL, Goletz JT, Gallagher TM. Palmitoylations on murine coronavirus spike proteins are essential for virion assembly and infectivity. J Virol 2006; 80:1280-9. [PMID: 16415005 PMCID: PMC1346925 DOI: 10.1128/jvi.80.3.1280-1289.2006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Coronavirus spike (S) proteins are palmitoylated at several cysteine residues clustered near their transmembrane-spanning domains. This is achieved by cellular palmitoyl acyltransferases (PATs), which can modify newly synthesized S proteins before they are assembled into virion envelopes at the intermediate compartment of the exocytic pathway. To address the importance of these fatty acylations to coronavirus infection, we exposed infected cells to 2-bromopalmitate (2-BP), a specific PAT inhibitor. 2-BP profoundly reduced the specific infectivities of murine coronaviruses at very low, nontoxic doses that were inert to alphavirus and rhabdovirus infections. 2-BP effected only two- to fivefold reductions in S palmitoylation, yet this correlated with reduced S complexing with virion membrane (M) proteins and consequent exclusion of S from virions. At defined 2-BP doses, underpalmitoylated S proteins instead trafficked to infected cell surfaces and elicited cell-cell membrane fusions, suggesting that the acyl chain adducts are more critical to virion assembly than to S-induced syncytial developments. These studies involving pharmacologic inhibition of S protein palmitoylation were complemented with molecular genetic analyses in which cysteine acylation substrates were mutated. Notably, some mutations (C1347F and C1348S) did not interfere with S incorporation into virions, indicating that only a subset of the cysteine-rich region provides the essential S-assembly functions. However, the C1347F/C1348S mutant viruses exhibited relatively low specific infectivities, similar to virions secreted from 2-BP-treated cultures. Our collective results indicate that the palmitate adducts on coronavirus S proteins are necessary in assembly and also in positioning the assembled envelope proteins for maximal infectivity.
Collapse
Affiliation(s)
- Edward B Thorp
- Department of Microbiology and Immunology, Loyola University Medical Center, 2160 South First Avenue, Maywood, IL 60153, USA
| | | | | | | | | |
Collapse
|
5
|
Hou H, Subramanian K, LaGrassa TJ, Markgraf D, Dietrich LEP, Urban J, Decker N, Ungermann C. The DHHC protein Pfa3 affects vacuole-associated palmitoylation of the fusion factor Vac8. Proc Natl Acad Sci U S A 2005; 102:17366-71. [PMID: 16301533 PMCID: PMC1297695 DOI: 10.1073/pnas.0508885102] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Indexed: 11/18/2022] Open
Abstract
Vacuole biogenesis depends on specific targeting and retention of peripheral membrane proteins. At least three palmitoylated proteins are found exclusively on yeast vacuoles: the fusion factor Vac8, the kinase Yck3, and a novel adaptor protein implicated in microautophagy, Meh1. Here, we analyze the role that putative acyltransferases of the DHHC family play in their localization and function. We find that Pfa3/Ynl326c is required for efficient localization of Vac8 to vacuoles in vivo, while Yck3 or Meh1 localization is not impaired in any of the seven DHHC deletions. Vacuole-associated Vac8 appears to be palmitoylated in a pfa3 mutant, but this population is refractive to further palmitoylation on isolated vacuoles. Vacuole morphology and inheritance, which both depend on Vac8 palmitoylation, appear normal, although there is a reduction in vacuole fusion. Interestingly, Pfa3 is required for the vacuolar localization of not only an SH4 domain that is targeted by myristate/palmitate (as in Vac8) but also one that is targeted by a myristate/basic stretch (as in Src). Our data indicate that Pfa3 has an important but not exclusive function for Vac8 localization to the vacuole.
Collapse
Affiliation(s)
- Haitong Hou
- Biochemie-Zentrum der Universität Heidelberg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Veit M. The human SNARE protein Ykt6 mediates its own palmitoylation at C-terminal cysteine residues. Biochem J 2005; 384:233-7. [PMID: 15479160 PMCID: PMC1134105 DOI: 10.1042/bj20041474] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The yeast SNARE (soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor) protein Ykt6 was shown to mediate palmitoylation of the fusion factor Vac8 in a reaction essential for the fusion of vacuoles. Here I present evidence that hYkt6 (human Ykt6) has self-palmitoylating activity. Incubation of recombinant hYkt6 with [3H]Pal-CoA ([3H]palmitoyl-CoA) leads to covalent attachment of palmitate to C-terminal cysteine residues. The N-terminal domain of human Ykt6 contains a Pal-CoA binding site and is required for the reaction.
Collapse
Affiliation(s)
- Michael Veit
- Department of Immunology and Molecular Biology, Vet.-Med. Faculty, Free University Berlin, Philippstrasse 13, 10115 Berlin, Federal Republic of Germany.
| |
Collapse
|
7
|
Dietrich LE, Ungermann C. On the mechanism of protein palmitoylation. EMBO Rep 2005; 5:1053-7. [PMID: 15520806 PMCID: PMC1299172 DOI: 10.1038/sj.embor.7400277] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Accepted: 08/26/2004] [Indexed: 11/08/2022] Open
Abstract
Protein palmitoylation or, more specifically, S-acylation is a reversible post-translational lipid modification. Despite the identification of several proteins that are altered in this way, our understanding of the enzymology of this process has been hampered by the lack of well-characterized acyltransferases. We now know of three proteins in Saccharomyces cerevisiae that promote palmitoylation: effector of Ras function (Erf2), ankyrin-repeat-containing protein (Akr1) and the SNARE protein Ykt6. Erf2 and Akr1 are integral membrane proteins that contain a cysteine-rich domain and an Asp-His-His-Cys motif, both of which catalyse acylation at the carboxyl terminus of their target proteins. Recently, we discovered that Ykt6 mediates the amino-terminal acylation of the fusion protein Vac8. Even though these three proteins differ in sequence, topology, size and substrate specificity, they might function in a similar manner. In this review, we discuss these observations in the context of a potential general mechanism of acylation.
Collapse
Affiliation(s)
- Lars E.P. Dietrich
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Christian Ungermann
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
- Tel: +49 6221 544 180; Fax: +49 6221 544 366;
| |
Collapse
|
8
|
Dietrich LEP, LaGrassa TJ, Rohde J, Cristodero M, Meiringer CTA, Ungermann C. ATP-independent control of Vac8 palmitoylation by a SNARE subcomplex on yeast vacuoles. J Biol Chem 2005; 280:15348-55. [PMID: 15701652 DOI: 10.1074/jbc.m410582200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Yeast vacuole fusion requires palmitoylated Vac8. We previously showed that Vac8 acylation occurs early in the fusion reaction, is blocked by antibodies against Sec18 (yeast N-ethylmaleimide-sensitive fusion protein (NSF)), and is mediated by the R-SNARE Ykt6. Here we analyzed the regulation of this reaction on purified vacuoles. We show that Vac8 acylation is restricted to a narrow time window, is independent of ATP hydrolysis by Sec18, and is stimulated by the ion chelator EDTA. Analysis of vacuole protein complexes indicated that Ykt6 is part of a complex distinct from the second R-SNARE, Nyv1. We speculate that during vacuole fusion, Nyv1 is the classical R-SNARE, whereas the Ykt6-containing complex has a novel function in Vac8 palmitoylation.
Collapse
Affiliation(s)
- Lars E P Dietrich
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | | | | | | | | | | |
Collapse
|
9
|
Smotrys JE, Linder ME. Palmitoylation of intracellular signaling proteins: regulation and function. Annu Rev Biochem 2004; 73:559-87. [PMID: 15189153 DOI: 10.1146/annurev.biochem.73.011303.073954] [Citation(s) in RCA: 452] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Protein S-palmitoylation is the thioester linkage of long-chain fatty acids to cysteine residues in proteins. Addition of palmitate to proteins facilitates their membrane interactions and trafficking, and it modulates protein-protein interactions and enzyme activity. The reversibility of palmitoylation makes it an attractive mechanism for regulating protein activity, and this feature has generated intensive investigation of this modification. The regulation of palmitoylation occurs through the actions of protein acyltransferases and protein acylthioesterases. Identification of the protein acyltransferases Erf2/Erf4 and Akr1 in yeast has provided new insight into the palmitoylation reaction. These molecules work in concert with thioesterases, such as acyl-protein thioesterase 1, to regulate the palmitoylation status of numerous signaling molecules, ultimately influencing their function. This review discusses the function and regulation of protein palmitoylation, focusing on intracellular proteins that participate in cell signaling or protein trafficking.
Collapse
Affiliation(s)
- Jessica E Smotrys
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
| | | |
Collapse
|
10
|
Dietrich LEP, Gurezka R, Veit M, Ungermann C. The SNARE Ykt6 mediates protein palmitoylation during an early stage of homotypic vacuole fusion. EMBO J 2003; 23:45-53. [PMID: 14685280 PMCID: PMC1271655 DOI: 10.1038/sj.emboj.7600015] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2003] [Accepted: 10/17/2003] [Indexed: 11/08/2022] Open
Abstract
The NSF homolog Sec18 initiates fusion of yeast vacuoles by disassembling cis-SNARE complexes during priming. Sec18 is also required for palmitoylation of the fusion factor Vac8, although the acylation machinery has not been identified. Here we show that the SNARE Ykt6 mediates Vac8 palmitoylation and acts during a novel subreaction of vacuole fusion. This subreaction is controlled by a Sec17-independent function of Sec18. Our data indicate that Ykt6 presents Pal-CoA via its N-terminal longin domain to Vac8, while transfer to Vac8's SH4 domain occurs spontaneously and not enzymatically. The conservation of Ykt6 and its localization to several organelles suggest that its acyltransferase activity may also be required in other intracellular fusion events.
Collapse
Affiliation(s)
- Lars EP Dietrich
- Biochemie-Zentrum Heidelberg (BZH), University of Heidelberg, Heidelberg, Germany
| | - Rolf Gurezka
- Biochemie-Zentrum Heidelberg (BZH), University of Heidelberg, Heidelberg, Germany
- Current address: BioReliance Manufacturing GmbH, Cernyring 22, 69115 Heidelberg, Germany
| | - Michael Veit
- Department of Immunology and Molecular Biology, Vet.-Med. Faculty of the Free University Berlin, Berlin, Germany
| | - Christian Ungermann
- Biochemie-Zentrum Heidelberg (BZH), University of Heidelberg, Heidelberg, Germany
- Biochemie-Zentrum Heidelberg (BZH), University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany. Tel.: +49 6221 544180; Fax: +49 6221 544366; E-mail:
| |
Collapse
|