1
|
Mendelson JB, Sternbach JD, Doyle MJ, Mills L, Hartweck LM, Tollison W, Carney JP, Lahti MT, Bianco RW, Kalra R, Kazmirczak F, Hindmarch C, Archer SL, Prins KW, Martin CM. Multi-omic and multispecies analysis of right ventricular dysfunction. J Heart Lung Transplant 2024; 43:303-313. [PMID: 37783299 PMCID: PMC10841898 DOI: 10.1016/j.healun.2023.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 09/14/2023] [Accepted: 09/28/2023] [Indexed: 10/04/2023] Open
Abstract
BACKGROUND Right ventricular failure (RVF) is a leading cause of morbidity and mortality in multiple cardiovascular diseases, but there are no treatments for RVF as therapeutic targets are not clearly defined. Contemporary transcriptomic/proteomic evaluations of RVF are predominately conducted in small animal studies, and data from large animal models are sparse. Moreover, a comparison of the molecular mediators of RVF across species is lacking. METHODS Transcriptomics and proteomics analyses defined the pathways associated with cardiac magnetic resonance imaging (MRI)-derived values of RV hypertrophy, dilation, and dysfunction in control and pulmonary artery banded (PAB) pigs. Publicly available data from rat monocrotaline-induced RVF and pulmonary arterial hypertension patients with preserved or impaired RV function were used to compare molecular responses across species. RESULTS PAB pigs displayed significant right ventricle/ventricular (RV) hypertrophy, dilation, and dysfunction as quantified by cardiac magnetic resonance imaging. Transcriptomic and proteomic analyses identified pathways associated with RV dysfunction and remodeling in PAB pigs. Surprisingly, disruptions in fatty acid oxidation (FAO) and electron transport chain (ETC) proteins were different across the 3 species. FAO and ETC proteins and transcripts were mostly downregulated in rats but were predominately upregulated in PAB pigs, which more closely matched the human response. All species exhibited similar dysregulation of the dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy pathways. CONCLUSIONS The porcine metabolic molecular signature was more similar to human RVF than rodents. These data suggest there may be divergent molecular responses of RVF across species, and pigs may more accurately recapitulate metabolic aspects of human RVF.
Collapse
Affiliation(s)
- Jenna B Mendelson
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota
| | - Jacob D Sternbach
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota
| | - Michelle J Doyle
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota
| | - Lauren Mills
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Lynn M Hartweck
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota
| | - Walt Tollison
- Department of Surgery, Experimental Surgical Services Laboratory, University of Minnesota, Minneapolis, Minnesota
| | - John P Carney
- Department of Surgery, Experimental Surgical Services Laboratory, University of Minnesota, Minneapolis, Minnesota
| | - Matthew T Lahti
- Department of Surgery, Experimental Surgical Services Laboratory, University of Minnesota, Minneapolis, Minnesota
| | - Richard W Bianco
- Department of Surgery, Experimental Surgical Services Laboratory, University of Minnesota, Minneapolis, Minnesota
| | - Rajat Kalra
- Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Felipe Kazmirczak
- Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Charles Hindmarch
- Queen's Cardiopulmonary Unit, Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Stephen L Archer
- Queen's Cardiopulmonary Unit, Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Kurt W Prins
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota; Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
| | - Cindy M Martin
- DeBakey Heart and Vascular Center, Houston Methodist, Houston, Texas
| |
Collapse
|
2
|
Mendelson JB, Sternbach JD, Doyle MJ, Mills L, Hartweck LM, Tollison W, Carney JP, Lahti MT, Bianco RW, Kalra R, Kazmirczak F, Hindmarch C, Archer SL, Prins KW, Martin CM. A Multi-omic and Multi-Species Analysis of Right Ventricular Failure. bioRxiv 2023:2023.02.08.527661. [PMID: 36798212 PMCID: PMC9934613 DOI: 10.1101/2023.02.08.527661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Right ventricular failure (RVF) is a leading cause of morbidity and mortality in multiple cardiovascular diseases, but there are no approved treatments for RVF as therapeutic targets are not clearly defined. Contemporary transcriptomic/proteomic evaluations of RVF are predominately conducted in small animal studies, and data from large animal models are sparse. Moreover, a comparison of the molecular mediators of RVF across species is lacking. Here, we used transcriptomics and proteomics analyses to define the molecular pathways associated with cardiac MRI-derived values of RV hypertrophy, dilation, and dysfunction in pulmonary artery banded (PAB) piglets. Publicly available data from rat monocrotaline-induced RVF and pulmonary arterial hypertension patients with preserved or impaired RV function were used to compare the three species. Transcriptomic and proteomic analyses identified multiple pathways that were associated with RV dysfunction and remodeling in PAB pigs. Surprisingly, disruptions in fatty acid oxidation (FAO) and electron transport chain (ETC) proteins were different across the three species. FAO and ETC proteins and transcripts were mostly downregulated in rats, but were predominately upregulated in PAB pigs, which more closely matched the human data. Thus, the pig PAB metabolic molecular signature was more similar to human RVF than rodents. These data suggest there may be divergent molecular responses of RVF across species, and that pigs more accurately recapitulate the metabolic aspects of human RVF.
Collapse
|
3
|
Prisco SZ, Hartweck LM, Kazmirczak F, Mendelson JB, Deng SL, Lahiri SK, Wehrens XH, Prins KW. Junctophilin-2 Regulates Mitochondrial Metabolism. bioRxiv 2023:2023.02.07.527576. [PMID: 36798293 PMCID: PMC9934637 DOI: 10.1101/2023.02.07.527576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Right ventricular dysfunction (RVD) is a risk factor for mortality in multiple cardiovascular diseases, but approaches to combat RVD are lacking. Therapies used for left heart failure are largely ineffective in RVD, and thus the identification of molecules that augment RV function could improve outcomes in a wide-array of cardiac limitations. Junctophilin-2 (JPH2) is an essential protein that plays important roles in cardiomyocytes, including calcium handling/maintenance of t-tubule structure and gene transcription. Additionally, JPH2 may regulate mitochondrial function as Jph2 knockout mice exhibit cardiomyocyte mitochondrial swelling and cristae derangements. Moreover, JPH2 knockdown in embryonic stem cell-derived cardiomyocytes induces downregulation of the mitochondrial protein mitofusin-2 (MFN2), which disrupts mitochondrial cristae structure and transmembrane potential. Impaired mitochondrial metabolism drives RVD, and here we evaluated the mitochondrial role of JPH2. We showed JPH2 directly interacts with MFN2, ablation of JPH2 suppresses mitochondrial biogenesis, oxidative capacity, and impairs lipid handling in iPSC-CM. Gene therapy with AAV9-JPH2 corrects RV mitochondrial morphological defects, mitochondrial fatty acid metabolism enzyme regulation, and restores the RV lipidomic signature in the monocrotaline rat model of RVD. Finally, AAV-JPH2 improves RV function without altering PAH severity, showing JPH2 provides an inotropic effect to the dysfunction RV.
Collapse
|
4
|
Prisco SZ, Hartweck LM, Rose L, Lima PDA, Thenappan T, Archer SL, Prins KW. Inflammatory Glycoprotein 130 Signaling Links Changes in Microtubules and Junctophilin-2 to Altered Mitochondrial Metabolism and Right Ventricular Contractility. Circ Heart Fail 2022; 15:e008574. [PMID: 34923829 PMCID: PMC8766918 DOI: 10.1161/circheartfailure.121.008574] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Right ventricular dysfunction (RVD) is the leading cause of death in pulmonary arterial hypertension (PAH), but no RV-specific therapy exists. We showed microtubule-mediated junctophilin-2 dysregulation (MT-JPH2 pathway) causes t-tubule disruption and RVD in rodent PAH, but the druggable regulators of this critical pathway are unknown. GP130 (glycoprotein 130) activation induces cardiomyocyte microtubule remodeling in vitro; however, the effects of GP130 signaling on the MT-JPH2 pathway and RVD resulting from PAH are undefined. METHODS Immunoblots quantified protein abundance, quantitative proteomics defined RV microtubule-interacting proteins (MT-interactome), metabolomics evaluated the RV metabolic signature, and transmission electron microscopy assessed RV cardiomyocyte mitochondrial morphology in control, monocrotaline, and monocrotaline-SC-144 (GP130 antagonist) rats. Echocardiography and pressure-volume loops defined the effects of SC-144 on RV-pulmonary artery coupling in monocrotaline rats (8-16 rats per group). In 73 patients with PAH, the relationship between interleukin-6, a GP130 ligand, and RVD was evaluated. RESULTS SC-144 decreased GP130 activation, which normalized MT-JPH2 protein expression and t-tubule structure in the monocrotaline RV. Proteomics analysis revealed SC-144 restored RV MT-interactome regulation. Ingenuity pathway analysis of dysregulated MT-interacting proteins identified a link between microtubules and mitochondrial function. Specifically, SC-144 prevented dysregulation of electron transport chain, Krebs cycle, and the fatty acid oxidation pathway proteins. Metabolomics profiling suggested SC-144 reduced glycolytic dependence, glutaminolysis induction, and enhanced fatty acid metabolism. Transmission electron microscopy and immunoblots indicated increased mitochondrial fission in the monocrotaline RV, which SC-144 mitigated. GP130 antagonism reduced RV hypertrophy and fibrosis and augmented RV-pulmonary artery coupling without altering PAH severity. In patients with PAH, higher interleukin-6 levels were associated with more severe RVD (RV fractional area change 23±12% versus 30±10%, P=0.002). CONCLUSIONS GP130 antagonism reduces MT-JPH2 dysregulation, corrects metabolic derangements in the RV, and improves RVD in monocrotaline rats.
Collapse
Affiliation(s)
- Sasha Z. Prisco
- Cardiovascular Division, Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN
| | - Lynn M. Hartweck
- Cardiovascular Division, Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN
| | - Lauren Rose
- Cardiovascular Division, Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN
| | | | - Thenappan Thenappan
- Cardiovascular Division, Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN
| | - Stephen L. Archer
- Queen’s CardioPulmonary Unit, Kingston, ON, Canada,Department of Medicine, Queen’s University, Kingston, ON, Canada
| | - Kurt W. Prins
- Cardiovascular Division, Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN
| |
Collapse
|
5
|
Bosnakovski D, Chan SSK, Recht OO, Hartweck LM, Gustafson CJ, Athman LL, Lowe DA, Kyba M. Author Correction: Muscle pathology from stochastic low level DUX4 expression in an FSHD mouse model. Nat Commun 2018; 9:856. [PMID: 29472544 PMCID: PMC5823909 DOI: 10.1038/s41467-018-03449-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In the originally published version of this Article, an incorrect grant number, RO1 NS083549, was acknowledged. The correct grant number is RO1 AR055685. This error has now been corrected in both the PDF and HTML versions of the Article.
Collapse
Affiliation(s)
- Darko Bosnakovski
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA.,Faculty of Medical Sciences, University Goce Delcev-Stip, Stip, 2000, Macedonia
| | - Sunny S K Chan
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Olivia O Recht
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Lynn M Hartweck
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Collin J Gustafson
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Laura L Athman
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Michael Kyba
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA. .,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA.
| |
Collapse
|
6
|
Bosnakovski D, Toso EA, Hartweck LM, Magli A, Lee HA, Thompson ER, Dandapat A, Perlingeiro RCR, Kyba M. The DUX4 homeodomains mediate inhibition of myogenesis and are functionally exchangeable with the Pax7 homeodomain. J Cell Sci 2017; 130:3685-3697. [PMID: 28935672 PMCID: PMC5702055 DOI: 10.1242/jcs.205427] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/11/2017] [Indexed: 01/15/2023] Open
Abstract
Facioscapulohumeral muscular dystrophy (FSHD) is caused by inappropriate expression of the double homeodomain protein DUX4. DUX4 has bimodal effects, inhibiting myogenic differentiation and blocking MyoD at low levels of expression, and killing myoblasts at high levels. Pax3 and Pax7, which contain related homeodomains, antagonize the cell death phenotype of DUX4 in C2C12 cells, suggesting some type of competitive interaction. Here, we show that the effects of DUX4 on differentiation and MyoD expression require the homeodomains but do not require the C-terminal activation domain of DUX4. We tested the set of equally related homeodomain proteins (Pax6, Pitx2c, OTX1, Rax, Hesx1, MIXL1 and Tbx1) and found that only Pax3 and Pax7 display phenotypic competition. Domain analysis on Pax3 revealed that the Pax3 homeodomain is necessary for phenotypic competition, but is not sufficient, as competition also requires the paired and transcriptional activation domains of Pax3. Remarkably, substitution mutants in which DUX4 homeodomains are replaced by Pax7 homeodomains retain the ability to inhibit differentiation and to induce cytotoxicity.
Collapse
Affiliation(s)
- Darko Bosnakovski
- Faculty of Medical Sciences, University Goce Delcev-Stip, 2000 Stip, R. Macedonia
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55014, USA
| | - Erik A Toso
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55014, USA
| | - Lynn M Hartweck
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55014, USA
| | - Alessandro Magli
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN 55104, USA
| | - Heather A Lee
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55014, USA
| | - Eliza R Thompson
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55014, USA
| | - Abhijit Dandapat
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55014, USA
| | - Rita C R Perlingeiro
- Lillehei Heart Institute, Department of Medicine, University of Minnesota, Minneapolis, MN 55104, USA
| | - Michael Kyba
- Lillehei Heart Institute, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55014, USA
| |
Collapse
|
7
|
Bosnakovski D, Chan SSK, Recht OO, Hartweck LM, Gustafson CJ, Athman LL, Lowe DA, Kyba M. Muscle pathology from stochastic low level DUX4 expression in an FSHD mouse model. Nat Commun 2017; 8:550. [PMID: 28916757 PMCID: PMC5601940 DOI: 10.1038/s41467-017-00730-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 07/21/2017] [Indexed: 11/09/2022] Open
Abstract
Facioscapulohumeral muscular dystrophy is a slowly progressive but devastating myopathy caused by loss of repression of the transcription factor DUX4; however, DUX4 expression is very low, and protein has not been detected directly in patient biopsies. Efforts to model DUX4 myopathy in mice have foundered either in being too severe, or in lacking muscle phenotypes. Here we show that the endogenous facioscapulohumeral muscular dystrophy-specific DUX4 polyadenylation signal is surprisingly inefficient, and use this finding to develop an facioscapulohumeral muscular dystrophy mouse model with muscle-specific doxycycline-regulated DUX4 expression. Very low expression levels, resulting in infrequent DUX4 + myonuclei, evoke a slow progressive degenerative myopathy. The degenerative process involves inflammation and a remarkable expansion in the fibroadipogenic progenitor compartment, leading to fibrosis. These animals also show high frequency hearing deficits and impaired skeletal muscle regeneration after injury. This mouse model will facilitate in vivo testing of therapeutics, and suggests the involvement of fibroadipogenic progenitors in facioscapulohumeral muscular dystrophy.Facioscapulohumeral muscular dystrophy is a severe myopathy that is caused by abnormal activation of DUX4, and for which a suitable mouse model does not exist. Here, the authors generate a novel mouse model with titratable expression of DUX4, and show that it recapitulates several features of the human pathology.
Collapse
Affiliation(s)
- Darko Bosnakovski
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA.,Faculty of Medical Sciences, University Goce Delcev - Stip, Stip, 2000, Macedonia
| | - Sunny S K Chan
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Olivia O Recht
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Lynn M Hartweck
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Collin J Gustafson
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Laura L Athman
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Dawn A Lowe
- Division of Rehabilitation Science and Division of Physical Therapy, Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Michael Kyba
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, 55455, USA. .,Department of Pediatrics, University of Minnesota, Minneapolis, MN, 55455, USA.
| |
Collapse
|
8
|
Zentella R, Hu J, Hsieh WP, Matsumoto PA, Dawdy A, Barnhill B, Oldenhof H, Hartweck LM, Maitra S, Thomas SG, Cockrell S, Boyce M, Shabanowitz J, Hunt DF, Olszewski NE, Sun TP. O-GlcNAcylation of master growth repressor DELLA by SECRET AGENT modulates multiple signaling pathways in Arabidopsis. Genes Dev 2016; 30:164-76. [PMID: 26773002 PMCID: PMC4719307 DOI: 10.1101/gad.270587.115] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Zentella et al. show that DELLAs are modified by the O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) SECRET AGENT (SEC) in Arabidopsis. O-GlcNAcylation of the DELLA protein REPRESSOR OF ga1-3 (RGA) inhibits RGA binding to four of its interactors—PHYTOCHROME-INTERACTING FACTOR3 (PIF3), PIF4, JASMONATE-ZIM DOMAIN1, and BRASSINAZOLE-RESISTANT1 (BZR1)—that are key regulators in light, jasmonate, and brassinosteroid signaling pathways, respectively. The DELLA family of transcription regulators functions as master growth repressors in plants by inhibiting phytohormone gibberellin (GA) signaling in response to developmental and environmental cues. DELLAs also play a central role in mediating cross-talk between GA and other signaling pathways via antagonistic direct interactions with key transcription factors. However, how these crucial protein–protein interactions can be dynamically regulated during plant development remains unclear. Here, we show that DELLAs are modified by the O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) SECRET AGENT (SEC) in Arabidopsis. O-GlcNAcylation of the DELLA protein REPRESSOR OF ga1-3 (RGA) inhibits RGA binding to four of its interactors—PHYTOCHROME-INTERACTING FACTOR3 (PIF3), PIF4, JASMONATE-ZIM DOMAIN1, and BRASSINAZOLE-RESISTANT1 (BZR1)—that are key regulators in light, jasmonate, and brassinosteroid signaling pathways, respectively. Consistent with this, the sec-null mutant displayed reduced responses to GA and brassinosteroid and showed decreased expression of several common target genes of DELLAs, BZR1, and PIFs. Our results reveal a direct role of OGT in repressing DELLA activity and indicate that O-GlcNAcylation of DELLAs provides a fine-tuning mechanism in coordinating multiple signaling activities during plant development.
Collapse
Affiliation(s)
- Rodolfo Zentella
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
| | - Jianhong Hu
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
| | - Wen-Ping Hsieh
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
| | - Peter A Matsumoto
- Department of Plant Biology, University of Minnesota, Saint Paul, Minnesota 55108, USA
| | - Andrew Dawdy
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA
| | - Benjamin Barnhill
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA
| | - Harriëtte Oldenhof
- Department of Plant Biology, University of Minnesota, Saint Paul, Minnesota 55108, USA
| | - Lynn M Hartweck
- Department of Plant Biology, University of Minnesota, Saint Paul, Minnesota 55108, USA
| | - Sushmit Maitra
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA
| | - Stephen G Thomas
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
| | - Shelley Cockrell
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
| | - Michael Boyce
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA
| | - Donald F Hunt
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA; Department of Pathology, University of Virginia, Charlottesville, Virginia 22901, USA
| | - Neil E Olszewski
- Department of Plant Biology, University of Minnesota, Saint Paul, Minnesota 55108, USA
| | - Tai-Ping Sun
- Department of Biology, Duke University, Durham, North Carolina 27708, USA
| |
Collapse
|
9
|
Dandapat A, Bosnakovski D, Hartweck LM, Arpke RW, Baltgalvis KA, Vang D, Baik J, Darabi R, Perlingeiro RCR, Hamra FK, Gupta K, Lowe DA, Kyba M. Dominant lethal pathologies in male mice engineered to contain an X-linked DUX4 transgene. Cell Rep 2014; 8:1484-96. [PMID: 25176645 PMCID: PMC4188423 DOI: 10.1016/j.celrep.2014.07.056] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 06/03/2014] [Accepted: 07/30/2014] [Indexed: 11/24/2022] Open
Abstract
Facioscapulohumeral muscular dystrophy (FSHD) is an enigmatic disease associated with epigenetic alterations in the subtelomeric heterochromatin of the D4Z4 macrosatellite repeat. Each repeat unit encodes DUX4, a gene that is normally silent in most tissues. Besides muscular loss, most patients suffer retinal vascular telangiectasias. To generate an animal model, we introduced a doxycycline-inducible transgene encoding DUX4 and 3' genomic DNA into a euchromatic region of the mouse X chromosome. Without induction, DUX4 RNA was expressed at low levels in many tissues and animals displayed a variety of unexpected dominant leaky phenotypes, including male-specific lethality. Remarkably, rare live-born males expressed DUX4 RNA in the retina and presented a retinal vascular telangiectasia. By using doxycycline to induce DUX4 expression in satellite cells, we observed impaired myogenesis in vitro and in vivo. This mouse model, which shows pathologies due to FSHD-related D4Z4 sequences, is likely to be useful for testing anti-DUX4 therapies in FSHD.
Collapse
Affiliation(s)
- Abhijit Dandapat
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA
| | - Darko Bosnakovski
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA
| | - Lynn M Hartweck
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA
| | - Robert W Arpke
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA
| | - Kristen A Baltgalvis
- Program in Physical Medicine and Rehabilitation, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA
| | - Derek Vang
- Vascular Biology Center, Division of Hematology, Oncology, and Transplantation, Department of Medicine MMC 480, 420 Delaware Street SE, University of Minnesota, Minneapolis, MN 55455, USA
| | - June Baik
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Medicine, University of Minnesota, 312 Church Street SE, Minneapolis, MN 55455, USA
| | - Radbod Darabi
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Medicine, University of Minnesota, 312 Church Street SE, Minneapolis, MN 55455, USA
| | - Rita C R Perlingeiro
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Medicine, University of Minnesota, 312 Church Street SE, Minneapolis, MN 55455, USA
| | - F Kent Hamra
- Department of Pharmacology, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Kalpna Gupta
- Vascular Biology Center, Division of Hematology, Oncology, and Transplantation, Department of Medicine MMC 480, 420 Delaware Street SE, University of Minnesota, Minneapolis, MN 55455, USA
| | - Dawn A Lowe
- Program in Physical Medicine and Rehabilitation, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA
| | - Michael Kyba
- Lillehei Heart Institute, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, 2231 6th Street SE, Minneapolis, MN 55455, USA.
| |
Collapse
|
10
|
Dandapat A, Hartweck LM, Bosnakovski D, Kyba M. Expression of the human FSHD-linked DUX4 gene induces neurogenesis during differentiation of murine embryonic stem cells. Stem Cells Dev 2013; 22:2440-8. [PMID: 23560660 DOI: 10.1089/scd.2012.0643] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Misexpression of the double homeodomain protein DUX4 in muscle is believed to cause facioscapulohumeral muscular dystrophy (FSHD). Although strategies are being devised to inhibit DUX4 activity in FSHD, there is little known about the normal function of this protein. Expression of DUX4 has been reported in pluripotent cells and testis. To test the idea that DUX4 may be involved in initiating a germ lineage program in pluripotent cells, we interrogated the effect of expressing the human DUX4 gene at different stages during in vitro differentiation of murine embryonic stem (ES) cells. We find that expression of even low levels of DUX4 is incompatible with pluripotency: DUX4-expressing ES cells downregulate pluripotency markers and rapidly differentiate even in the presence of leukemia inhibitory factor (LIF) and bone morphogenetic protein 4 (BMP4). Transcriptional profiling revealed unexpectedly that DUX4 induced a neurectodermal program. Embryoid bodies exposed to a pulse of DUX4 expression displayed severely inhibited mesodermal differentiation, but acquired neurogenic potential. In a serum-containing medium in which neurogenic differentiation is minimal, DUX4 expression served as a neural-inducing factor, enabling the differentiation of Tuj1+ neurites. These data suggest that besides effects in muscle and germ cells, the involvement of DUX4 in neurogenesis should be considered as anti-DUX4 therapies are developed.
Collapse
Affiliation(s)
- Abhijit Dandapat
- Department of Pediatrics, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | | | | | | |
Collapse
|
11
|
Hartweck LM, Anderson LJ, Lemmers RJ, Dandapat A, Toso EA, Dalton JC, Tawil R, Day JW, van der Maarel SM, Kyba M. A focal domain of extreme demethylation within D4Z4 in FSHD2. Neurology 2013; 80:392-9. [PMID: 23284062 DOI: 10.1212/wnl.0b013e31827f075c] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Facioscapulohumeral muscular dystrophy (FSHD) is a neuromuscular disease with an unclear genetic mechanism. Most patients have a contraction of the D4Z4 macrosatellite repeat array at 4qter, which is thought to cause partial demethylation (FSHD1) of the contracted allele. Demethylation has been surveyed at 3 restriction enzyme sites in the first repeat and only a single site across the entire array, and current models postulate that a generalized D4Z4 chromatin alteration causes FSHD. The background of normal alleles has confounded the study of epigenetic alterations; however, rare patients (FSHD2) have a form of the disease in which demethylation is global, i.e., on all D4Z4 elements throughout the genome. Our objective was to take advantage of the global nature of FSHD2 to identify where disease-relevant methylation changes occur within D4Z4. METHODS Using bisulfite sequencing of DNA from blood and myoblast cells, methylation levels at 74 CpG sites across 3 disparate regions within D4Z4 were measured in FSHD2 patients and controls. RESULTS We found that rates of demethylation caused by FSHD2 are not consistent across D4Z4. We identified a focal region of extreme demethylation within a 5' domain, which we named DR1. Other D4Z4 regions, including the DUX4 ORF, were hypomethylated but to a much lesser extent. CONCLUSIONS These data challenge the simple view that FSHD is caused by a broad "opening" of D4Z4 and lead us to postulate that the region of focal demethylation is the site of action of the key D4Z4 chromatin regulatory factors that go awry in FSHD.
Collapse
Affiliation(s)
- Lynn M Hartweck
- Department of Pediatrics and Lillehei Heart Institute, Minneapolis, MN, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Olszewski NE, West CM, Sassi SO, Hartweck LM. O-GlcNAc protein modification in plants: Evolution and function. Biochim Biophys Acta Gen Subj 2009; 1800:49-56. [PMID: 19961900 DOI: 10.1016/j.bbagen.2009.11.016] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2009] [Revised: 11/19/2009] [Accepted: 11/25/2009] [Indexed: 11/30/2022]
Abstract
The role in plants of posttranslational modification of proteins with O-linked N-acetylglucosamine and the evolution and function of O-GlcNAc transferases responsible for this modification are reviewed. Phylogenetic analysis of eukaryotic O-GlcNAc transferases (OGTs) leads us to propose that plants have two distinct OGTs, SEC- and SPY-like, that originated in prokaryotes. Animals and some fungi have a SEC-like enzyme while plants have both. Green algae and some members of the Apicomplexa and amoebozoa have the SPY-like enzyme. Interestingly the progenitor of the Apicomplexa lineage likely had a photosynthetic plastid that persists in a degenerated form in some species, raising the possibility that plant SPY-like OGTs are derived from a photosynthetic endosymbiont. OGTs have multiple tetratricopeptide repeats (TPRs) that within the SEC- and SPY-like classes exhibit evidence of strong selective pressure on specific repeats, suggesting that the function of these repeats is conserved. SPY-like and SEC-like OGTs have both unique and overlapping roles in the plant. The phenotypes of sec and spy single and double mutants indicate that O-GlcNAc modification is essential and that it affects diverse plant processes including response to hormones and environmental signals, circadian rhythms, development, intercellular transport and virus infection. The mechanistic details of how O-GlcNAc modification affects these processes are largely unknown. A major impediment to understanding this is the lack of knowledge of the identities of the modified proteins.
Collapse
Affiliation(s)
- Neil E Olszewski
- Department of Plant Biology, Microbial and Plant Genomics Institute, 250 Biological Sciences Center, 1445 Gortner Ave., St. Paul, MN 55108, USA.
| | | | | | | |
Collapse
|
13
|
Abstract
This review covers recent advances in gibberellin (GA) signaling. GA signaling is now understood to hinge on DELLA proteins. DELLAs negatively regulate GA response by activating the promoters of several genes including Xerico, which upregulates the abscisic acid pathway which is antagonistic to GA. DELLAs also promote transcription of the GA receptor, GIBBERELLIN INSENSITIVE DWARF 1 (GID1) and indirectly regulate GA biosynthesis genes enhancing GA responsiveness and feedback control. A structural analysis of GID1 provides a model for understanding GA signaling. GA binds within a pocket of GID1, changes GID1 conformation and increases the affinity of GID1 for DELLA proteins. GA/GID1/DELLA has increased affinity for an F-Box protein and DELLAs are subsequently degraded via the proteasome. Therefore, GA induces growth through degradation of the DELLAs. The binding of DELLA proteins to three of the PHYTOCHROME INTERACTING FACTOR (PIF) proteins integrates light and GA signaling pathways. This binding prevents PIFs 3, 4, and 5 from functioning as positive transcriptional regulators of growth in the dark. Since PIFs are degraded in light, these PIFs can only function in the combined absence of light and presence of GA. New analyses suggest that GA signaling evolved at the same time or just after the plant vascular system and before plants acquired the capacity for seed reproduction. An analysis of sequences cloned from Physcomitrella suggests that GID1 and DELLAs were the first to evolve but did not initially interact. The more recently diverging spike moss Selaginella has all the genes required for GA biosynthesis and signaling, but the role of GA response in Selaginella physiology remains a mystery.
Collapse
Affiliation(s)
- Lynn M Hartweck
- Department of Plant Biology, 250 Biological Sciences Center, 1445 Gortner Ave, St Paul, MN 55108, USA.
| |
Collapse
|
14
|
de Jesús Pérez J, Juárez S, Chen D, Scott CL, Hartweck LM, Olszewski NE, García JA. Mapping of two O-GlcNAc modification sites in the capsid protein of the potyvirus Plum pox virus. FEBS Lett 2006; 580:5822-8. [PMID: 17014851 DOI: 10.1016/j.febslet.2006.09.041] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 09/15/2006] [Accepted: 09/15/2006] [Indexed: 11/24/2022]
Abstract
A large number of O-linked N-acetylglucosamine (O-GlcNAc) residues have been mapped in vertebrate proteins, however targets of O-GlcNAcylation in plants still have not been characterized. We show here that O-GlcNAcylation of the N-terminal region of the capsid protein of Plum pox virus resembles that of animal proteins in introducing O-GlcNAc monomers. Thr-19 and Thr-24 were specifically O-GlcNAcylated. These residues are surrounded by amino acids typical of animal O-GlcNAc acceptor sites, suggesting that the specificity of O-GlcNAc transferases is conserved among plants and animals. In laboratory conditions, mutations preventing O-GlcNAcylation of Thr-19 and Thr-24 did not have noticeable effects on PPV competence to infect Prunus persicae or Nicotiana clevelandii. However, the fact that Thr-19 and Thr-24 are highly conserved among different PPV strains suggests that their O-GlcNAc modification could be relevant for efficient competitiveness in natural conditions.
Collapse
Affiliation(s)
- José de Jesús Pérez
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología (CSIC), Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | | | | | | | | | | | | |
Collapse
|
15
|
Scott CL, Hartweck LM, de Jesús Pérez J, Chen D, García JA, Olszewski NE. SECRET AGENT, an Arabidopsis thaliana O-GlcNAc transferase, modifies the Plum pox virus capsid protein. FEBS Lett 2006; 580:5829-35. [PMID: 17027982 DOI: 10.1016/j.febslet.2006.09.046] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2006] [Revised: 09/15/2006] [Accepted: 09/15/2006] [Indexed: 12/01/2022]
Abstract
The capsid protein of Plum pox virus (PPV-CP) is modified with O-linked GlcNAc (O-GlcNAc). While Arabidopsis has two O-GlcNAc transferases, SECRET AGENT (SEC) and SPINDLY (SPY), previous work suggests that SEC modifies PPV-CP and that the modification plays a role in the infection process. Here, we show that when co-expressed in Escherichia coli SEC modifies PPV-CP. Deletion mapping and site-directed mutagenesis identified three threonine and a serine located near the N-terminus of PPV-CP that are modified by SEC. Two of these threonines have recently been shown to be modified in virus from plants suggesting that SEC has the same specificity in plants and E. coli.
Collapse
Affiliation(s)
- Cheryl L Scott
- Department of Plant Biology, University of Minnesota, 1445 Gortner Avenue, 250 Biological Sciences Center, St. Paul, MN 55108, USA
| | | | | | | | | | | |
Collapse
|
16
|
Hartweck LM, Olszewski NE. Rice GIBBERELLIN INSENSITIVE DWARF1 is a gibberellin receptor that illuminates and raises questions about GA signaling. Plant Cell 2006; 18:278-82. [PMID: 16452510 PMCID: PMC1356538 DOI: 10.1105/tpc.105.039958] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Affiliation(s)
- Lynn M Hartweck
- Department of Plant Biology, University of Minesota, St. Paul, MN 55108, USA
| | | |
Collapse
|
17
|
Hartweck LM, Genger RK, Grey WM, Olszewski NE. SECRET AGENT and SPINDLY have overlapping roles in the development of Arabidopsis thaliana L. Heyn. J Exp Bot 2006; 57:865-75. [PMID: 16473894 DOI: 10.1093/jxb/erj071] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
O-GlcNAc transferase (OGT) catalyses transfer of GlcNAc (N-acetylglucosamine) to serine or threonine of proteins. The Arabidopsis OGTs, SECRET AGENT (SEC) and SPINDLY (SPY) have overlapping functions during gametogenesis and embryogenesis. SPY functions in a number of processes including circadian, light, and gibberellin (GA) responses. The role of SEC in plant development and GA signalling was investigated by determining the phenotypes of sec-1 and sec-2 plants and the expression pattern of SEC. Similar to SPY, SEC transcripts were ubiquitous. Although there is no evidence of transcript-level regulation by other factors, SEC mRNA levels are elevated in spy plants and SPY mRNA levels are elevated in sec plants. sec-1 and sec-2 plants exhibited few of the defects observed in spy plants and had wild-type GA responses. Compared with wild type, sec plants produced leaves at a reduced rate. Haplo-insufficiency at SEC in a spy ga1 double mutant background suppressed spy during germination and enhanced the production of ovaries with four carpels by spy. By contrast, SPY haplo-insufficiency in a sec ga1 double mutant background caused a novel phenotype, production of a proliferation of pin-like structures instead of a floral shoot. These results are consistent with SEC function overlapping with SPY for leaf production and reproductive development.
Collapse
Affiliation(s)
- Lynn M Hartweck
- Department of Plant Biology, University of Minnesota, 250 Biological Sciences Center, 1445 Gortner Ave., St Paul, 55108, USA
| | | | | | | |
Collapse
|
18
|
Hartweck LM, Scott CL, Olszewski NE. Two O-linked N-acetylglucosamine transferase genes of Arabidopsis thaliana L. Heynh. have overlapping functions necessary for gamete and seed development. Genetics 2002; 161:1279-91. [PMID: 12136030 PMCID: PMC1462182 DOI: 10.1093/genetics/161.3.1279] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Arabidopsis SECRET AGENT (SEC) and SPINDLY (SPY) proteins are similar to animal O-linked N-acetylglucosamine transferases (OGTs). OGTs catalyze the transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to Ser/Thr residues of proteins. In animals, O-GlcNAcylation has been shown to affect protein activity, stability, and/or localization. SEC protein expressed in Escherichia coli had autocatalytic OGT activity. To determine the function of SEC in plants, two tDNA insertional mutants were identified and analyzed. Although sec mutant plants did not exhibit obvious phenotypes, sec and spy mutations had a synthetic lethal interaction. This lethality was incompletely penetrant in gametes and completely penetrant postfertilization. The rate of both female and male sec spy gamete transmission was higher in plants heterozygous for both mutations than in plants heterozygous for sec and homozygous for spy. Double-mutant embryos aborted at various stages of development and no double-mutant seedlings were obtained. These results indicate that OGT activity is required during gametogenesis and embryogenesis with lethality occurring when parentally derived SEC, SPY, and/or O-GlcNAcylated proteins become limiting.
Collapse
Affiliation(s)
- Lynn M Hartweck
- Department of Plant Biology and Plant Molecular Genetics Institute, University of Minnesota, 220 Biological Sciences Center, 1445 Gortner Avenue, St Paul, MN 55108, USA
| | | | | |
Collapse
|
19
|
Abstract
Highly degenerate primers to conserved regions of the eukaryotic phosphoinositol-specific phospholipase C (PLC) were used to amplify fragments of plant PLCs from Arabidopsis thaliana genomic DNA. Eight completely different fragment sequences that showed high homology to PLCs of both animals and plants were isolated. The variation between these putative PLCs was high and suggests that, like animals, plants have multiple isoforms of PLC. Using one of the PCR clones, we isolated a corresponding full-length Arabidopsis PLC gene (ATHATPLC1G), and sequence analysis indicated that it was most like a delta-type PLC. This gene is 2.5 kb and contains seven introns, all but one of which has intron/exon border sequences that conform to the Arabidopsis consensus. The structural complexity of the gene is relatively simple compared to mammalian beta-type PLCs that can be 15 kb long with up to 30 introns. The plant gene is a single copy and was mapped to four Arabidopsis YACs, one located on chromosome 2. The promoter region contained two TATA-like elements at -43 and -185 and other putative regulatory elements that suggest that this PLC is hormonally regulated. This is the first plant PLC gene and the first delta type-PLC gene from a higher organism to be sequenced.
Collapse
Affiliation(s)
- L M Hartweck
- Commonwealth Scientific and Industrial Research Organisation, Plant Industry, Canberra, ACT, Australia
| | | | | |
Collapse
|
20
|
Hartweck LM, Vogelzang RD, Osborn TC. Characterization and comparison of arcelin seed protein variants from common bean. Plant Physiol 1991; 97:204-11. [PMID: 16668372 PMCID: PMC1080985 DOI: 10.1104/pp.97.1.204] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Four variants of arcelin, an insecticidal seed storage protein of bean, Phaseolus vulgaris L., were investigated. Each variant (arcelin-1, -2, -3, and -4) was purified, and solubilities and M(r)s were determined. For arcelins-1, -2, and -4, the isoelectric points, hemagglutinating activities, immunological cross-reactivities, and N-terminal amino acid sequences were determined. On the basis of native and denatured M(r)s, the variants were classified as being composed of dimer protein (arcelin-2), tetramer protein (arcelins-3 and -4), or both dimer and tetramer proteins (arcelin-1). Although the dimer proteins (arcelins-1d and -2) could be distinguished by M(r)s and isoelectric points, they were identical for their first 37 N-terminal amino acids and had similar immunological cross-reactions, and bean lines containing these variants had a DNA restriction fragment in common. The tetramer proteins arcelin-1t and arcelin-4 also could be distinguished from each other based on M(r)s and isoelectric points; however, they had similar immunological cross-reactions and they were 77 to 93% identical for N-terminal amino acid composition. The similarities among arcelin variants, phytohemagglutinin, and a bean alpha-amylase inhibitor suggest that they are all encoded by related members of a lectin gene family.
Collapse
Affiliation(s)
- L M Hartweck
- Department of Agronomy, University of Wisconsin, Madison, Wisconsin 53706
| | | | | |
Collapse
|