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Dikiy I, Ramlall TF, Eliezer D. ¹H, ¹³C, and ¹⁵N backbone resonance assignments of the L124D mutant of StAR-related lipid transfer domain protein 4 (StARD4). Biomol NMR Assign 2013; 7:245-248. [PMID: 22918595 PMCID: PMC3594388 DOI: 10.1007/s12104-012-9419-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 08/10/2012] [Indexed: 06/01/2023]
Abstract
Protein-mediated cholesterol trafficking is central to maintaining cholesterol homeostasis in cells. START (Steroidogenic acute regulatory protein-related lipid transfer) domains constitute a sterol and lipid binding motif and the START domain protein StARD4 typifies a small family of mammalian sterol transport proteins. StARD4 consists of a single START domain and has been reported to act as a general cholesterol transporter in cells. However, the structural basis of cholesterol uptake and transport is not well understood and no cholesterol-bound START domain structures have been reported. We have undertaken the study of cholesterol binding and transport by StARD4 using solution state NMR spectroscopy. To this end, we report nearly complete (1)H, (15)N, and (13)C backbone resonance assignments of an inactive but well behaved mutant (L124D) of StARD4.
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Affiliation(s)
- Igor Dikiy
- Department of Biochemistry and Program in Structural Biology, Weill Cornell Medical College, New York, NY, USA
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Rodriguez-Agudo D, Calderon-Dominguez M, Ren S, Marques D, Redford K, Medina-Torres MA, Hylemon P, Gil G, Pandak WM. Subcellular localization and regulation of StarD4 protein in macrophages and fibroblasts. Biochim Biophys Acta 2011; 1811:597-606. [PMID: 21767660 PMCID: PMC3156897 DOI: 10.1016/j.bbalip.2011.06.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 06/07/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
StarD4 is a member of the StarD4 subfamily of START domain proteins with a characteristic lipid binding pocket specific for cholesterol. The objective of this study was to define StarD4 subcellular localization, regulation, and function. Immunobloting showed that StarD4 is highly expressed in the mouse fibroblast cell line 3T3-L1, in human THP-1 macrophages, Kupffer cells (liver macrophages), and hepatocytes. In 3T3-L1 cells and THP-1 macrophages, StarD4 protein appeared localized to the cytoplasm and the endoplasmic reticulum (ER). More specifically, in THP-1 macrophages StarD4 co-localized to areas of the ER enriched in Acyl-CoA:cholesterol acyltransferase-1 (ACAT-1), and was closely associated with budding lipid droplets. The addition of purified StarD4 recombinant protein to an in vitro assay increased ACAT activity 2-fold, indicating that StarD4 serves as a rate-limiting step in cholesteryl ester formation by delivering cholesterol to ACAT-1-enriched ER. In addition, StarD4 protein was found to be highly regulated and to redistribute in response to sterol levels. In summary, these observations, together with our previous findings demonstrating the ability of increased StarD4 expression to increase bile acid synthesis and cholesteryl ester formation, provide strong evidence for StarD4 as a highly regulated, non-vesicular, directional, intracellular transporter of cholesterol which plays a key role in the maintenance of intracellular cholesterol homeostasis.
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Affiliation(s)
| | - Maria Calderon-Dominguez
- Department of Medicine, Veterans Affairs Medical Center and Virginia Commonwealth University; Richmond, Virginia,Department of Molecular Biology and Biochemistry, Universidad de Malaga, Spain
| | - Shunlin Ren
- Department of Medicine, Veterans Affairs Medical Center and Virginia Commonwealth University; Richmond, Virginia
| | - Dalila Marques
- Department of Medicine, Veterans Affairs Medical Center and Virginia Commonwealth University; Richmond, Virginia
| | - Kaye Redford
- Department of Medicine, Veterans Affairs Medical Center and Virginia Commonwealth University; Richmond, Virginia
| | | | - Phillip Hylemon
- Department of Microbiology/Immunology, Veterans Affairs Medical Center and Virginia Commonwealth University; Richmond, Virginia
| | - Gregorio Gil
- Department of Biochemistry and Molecular Biology, Veterans Affairs Medical Center and Virginia Commonwealth University; Richmond, Virginia
| | - William M. Pandak
- Department of Medicine, Veterans Affairs Medical Center and Virginia Commonwealth University; Richmond, Virginia
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Zhang F, Zuo K, Zhang J, Liu X, Zhang L, Sun X, Tang K. An L1 box binding protein, GbML1, interacts with GbMYB25 to control cotton fibre development. J Exp Bot 2010; 61:3599-613. [PMID: 20667961 PMCID: PMC2921199 DOI: 10.1093/jxb/erq173] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/24/2010] [Accepted: 05/25/2010] [Indexed: 05/19/2023]
Abstract
Transcription factors play key roles in plant development through their interaction with cis-elements and/or other transcription factors. A HD-Zip IV family transcription factor, Gossypium barbadense Meristem Layer 1 (GbML1) has been identified and characterized here. GbML1 specifically bound to the L1 box and the promoters of GbML1 and GbRDL1. GbML1 physically interacted with a key regulator of cotton fibre development, GbMYB25. Truncated and point mutation assays indicated the START-SAD domain was required for the binding to the C terminal domain (CTD) of GbMYB25. GbML1 overexpression in Arabidopsis increased the number of trichomes on stems and leaves and increased the accumulation of anthocyanin in leaves. Taken together, the L1 box binding protein, GbML1 was identified as the first partner for GbMYB25 and the role of START domain was discovered to be a protein binding domain in plants. Our findings will help the improvement of cotton fibre production and the understanding of the key role of HD-Zip family and MYB family in plants.
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Affiliation(s)
- Fei Zhang
- Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Kaijing Zuo
- Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Jieqiong Zhang
- Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Xiang Liu
- Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Lida Zhang
- Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Xiaofen Sun
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, People's Republic of China
| | - Kexuan Tang
- Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- To whom correspondence should be addressed. E-mail: or
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Abstract
The phytohormone abscisic acid (ABA) plays a central role in plant development and in plant adaptation to both biotic and abiotic stressors. In recent years, knowledge of ABA metabolism and signal transduction has advanced rapidly to provide detailed glimpses of the hormone's activities at the molecular level. Despite this progress, many gaps in understanding have remained, particularly at the early stages of ABA perception by the plant cell. The search for an ABA receptor protein has produced multiple candidates, including GCR2, GTG1, and GTG2, and CHLH. In addition to these candidates, in 2009 several research groups converged on a novel family of Arabidopsis proteins that bind ABA, and thereby interact directly with a class of protein phosphatases that are well known as critical players in ABA signal transduction. The PYR/PYL/RCAR receptor family is homologous to the Bet v 1-fold and START domain proteins. It consists of 14 members, nearly all of which appear capable of participating in an ABA receptor-signal complex that responds to the hormone by activating the transcription of ABA-responsive genes. Evidence is provided here that PYR/PYL/RCAR receptors can also drive the phosphorylation of the slow anion channel SLAC1 to provide a fast and timely response to the ABA signal. Crystallographic studies have vividly shown the mechanics of ABA binding to PYR/PYL/RCAR receptors, presenting a model that bears some resemblance to the binding of gibberellins to GID1 receptors. Since this ABA receptor family is highly conserved in crop species, its discovery is likely to usher a new wave of progress in the elucidation and manipulation of plant stress responses in agricultural settings.
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Affiliation(s)
- John P. Klingler
- Plant Stress Genomics Research Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Department of Botany and Plant Sciences, 2150 Batchelor Hall, University of California at Riverside, Riverside, California 92521, USA
| | - Giorgia Batelli
- Plant Stress Genomics Research Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Department of Botany and Plant Sciences, 2150 Batchelor Hall, University of California at Riverside, Riverside, California 92521, USA
| | - Jian-Kang Zhu
- Plant Stress Genomics Research Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Department of Botany and Plant Sciences, 2150 Batchelor Hall, University of California at Riverside, Riverside, California 92521, USA
- To whom correspondence should be addressed: E-mail:
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Mercier KA, Mueller GA, Acton TB, Xiao R, Montelione GT, Powers R. (1)H, (13)C, and (15)N NMR assignments for the Bacillus subtilis yndB START domain. Biomol NMR Assign 2009; 3:191-194. [PMID: 19888688 PMCID: PMC4991356 DOI: 10.1007/s12104-009-9172-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Accepted: 06/03/2009] [Indexed: 05/28/2023]
Abstract
The steroidogenic acute regulatory-related lipid transfer (START) domain is found in both eukaryotes and prokaryotes, with putative functions including signal transduction, transcriptional regulation, GTPase activation and thioester hydrolysis. Here we report the near complete (1)H, (15)N and (13)C backbone and side chain NMR resonance assignments for the Bacillus subtilis START domain protein yndB.
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Affiliation(s)
- Kelly A Mercier
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA.
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Pan HJ, Agate DS, King BL, Wu MK, Roderick SL, Leiter EH, Cohen DE. A polymorphism in New Zealand inbred mouse strains that inactivates phosphatidylcholine transfer protein. FEBS Lett 2006; 580:5953-8. [PMID: 17046758 PMCID: PMC1693963 DOI: 10.1016/j.febslet.2006.09.066] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [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: 09/08/2006] [Accepted: 09/26/2006] [Indexed: 11/23/2022]
Abstract
New Zealand obese (NZO/HlLt) male mice develop polygenic diabetes and altered phosphatidylcholine metabolism. The gene encoding phosphatidylcholine transfer protein (PC-TP) is sited within the support interval for Nidd3, a recessive NZO-derived locus on Chromosome 11 identified by prior segregation analysis between NZO/HlLt and NON/Lt. Sequence analysis revealed that the NZO-derived PC-TP contained a non-synonymous point mutation that resulted in an Arg120His substitution, which was shared by the related NZB/BlNJ and NZW/LacJ mouse strains. Consistent with the structure-based predictions, functional studies demonstrated that Arg120His PC-TP was inactive, suggesting that this mutation contributes to the deficiencies in phosphatidylcholine metabolism observed in NZO mice.
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Affiliation(s)
- Huei-Ju Pan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Diana S. Agate
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | | | - Michele K. Wu
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School and Harvard-Massachusetts Institute of Technology, Division of Health Sciences and Technology, Boston, MA 02115
| | - Steven L. Roderick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | | | - David E. Cohen
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School and Harvard-Massachusetts Institute of Technology, Division of Health Sciences and Technology, Boston, MA 02115
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