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Farheen A, Case NT, MacAlpine J, Fu C, Robbins N, Cowen LE. The putative prenyltransferase Nus1 is required for filamentation in the human fungal pathogen Candida albicans. G3 (BETHESDA, MD.) 2024; 14:jkae124. [PMID: 38874344 PMCID: PMC11304969 DOI: 10.1093/g3journal/jkae124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 04/03/2024] [Accepted: 05/31/2024] [Indexed: 06/15/2024]
Abstract
Candida albicans is a major fungal pathogen of humans that can cause serious systemic infections in vulnerable immunocompromised populations. One of its virulence attributes is its capacity to transition between yeast and filamentous morphologies, but our understanding of this process remains incomplete. Here, we analyzed data from a functional genomic screen performed with the C. albicans Gene Replacement And Conditional Expression collection to identify genes crucial for morphogenesis in host-relevant conditions. Through manual scoring of microscopy images coupled with analysis of each image using a deep learning-based method termed Candescence, we identified 307 genes important for filamentation in tissue culture medium at 37°C with 5% CO2. One such factor was orf19.5963, which is predicted to encode the prenyltransferase Nus1 based on sequence homology to Saccharomyces cerevisiae. We further showed that Nus1 and its predicted interacting partner Rer2 are important for filamentation in multiple liquid filament-inducing conditions as well as for wrinkly colony formation on solid agar. Finally, we highlight that Nus1 and Rer2 likely govern C. albicans morphogenesis due to their importance in intracellular trafficking, as well as maintaining lipid homeostasis. Overall, this work identifies Nus1 and Rer2 as important regulators of C. albicans filamentation and highlights the power of functional genomic screens in advancing our understanding of gene function in human fungal pathogens.
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Affiliation(s)
- Aiman Farheen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Nicola T Case
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Jessie MacAlpine
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Ci Fu
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
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Xu D, Wang M, Zhang X, Mao H, Xu H, Zhang B, Zeng X, Li F. The Putative Cytochrome b5 Domain-Containing Protein CaDap1 Homologue Is Involved in Antifungal Drug Tolerance, Cell Wall Chitin Maintenance, and Virulence in Candida albicans. J Fungi (Basel) 2024; 10:316. [PMID: 38786671 PMCID: PMC11122062 DOI: 10.3390/jof10050316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 05/25/2024] Open
Abstract
Candida albicans (Ca), a prominent opportunistic fungal pathogen in humans, has garnered considerable attention due to its infectious properties. Herein, we have identified and characterized CaCDAP1 (Ca orf19.1034), a homolog of ScDAP1 found in Saccharomyces cerevisiae. CaCDAP1 encodes a 183-amino acid protein with a conserved cytochrome b5-like heme-binding domain. The deletion of CaDAP1 renders Ca cells susceptible to caspofungin and terbinafine. CaDAP1 deletion confers resistance to Congo Red and Calcofluor White, and sensitivity to sodium dodecyl sulfate. The deletion of CaDAP1 results in a 50% reduction in chitin content within the cell wall, the downregulation of phosphorylation levels in CaMkc1, and the upregulation of phosphorylation levels in CaCek1. Notably, CaDAP1 deletion results in the abnormal hyphal development of Ca cells and diminishes virulence in a mouse systemic infection model. Thus, CaDAP1 emerges as a critical regulator governing cellular responses to antifungal drugs, the synthesis of cell wall chitin, and virulence in Ca.
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Affiliation(s)
- Dayong Xu
- College of Life Sciences, Huaibei Normal University, Huaibei 235000, China; (M.W.); (X.Z.); (H.M.); (H.X.); (B.Z.); (X.Z.)
| | | | | | | | | | | | | | - Feng Li
- College of Life Sciences, Huaibei Normal University, Huaibei 235000, China; (M.W.); (X.Z.); (H.M.); (H.X.); (B.Z.); (X.Z.)
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Tian S, Bing J, Chu Y, Li H, Wang Q, Cheng S, Chen J, Shang H. Phenotypic and genetic features of a novel clinically isolated rough morphotype Candida auris. Front Microbiol 2023; 14:1174878. [PMID: 37350781 PMCID: PMC10282645 DOI: 10.3389/fmicb.2023.1174878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/23/2023] [Indexed: 06/24/2023] Open
Abstract
Introduction Candida auris is a newly emerging pathogenic fungus of global concern and has been defined by the World Health Organization (WHO) as a member of the critical group of the most health-threatening fungi. Methods This study reveals and reports for the first time that a rough morphotype C. auris strain causes urinary tract infections in non-intensive care unit (ICU) inpatients. Furthermore, the morphology, the scanning electronmicroscopy (SEM), Whole-genome resequencing and RNA sequencing of C. auris possessing rough morphotype colonies compared to their smooth morphotype counterparts. Results The newly identified phenotypic variation of C. auris appears round, convex, dry, and burr-like with a rough texture. SEM shows that rough type C. auris has a rough and uneven colony surface with radial wrinkles and irregular spore arrangement. Cells of the rough morphotype C. auris naturally aggregate into clusters with tight connections in the liquid, and it seems that the cell division is incomplete. A genome-wide analysis of the rough type C. auris confirmed its genetic association with the smooth type of C. auris prevalent in China (Shenyang) two years ago; however, single nucleotide polymorphism (SNP) mutations of five genes (ACE2, IFF6, RER2, UTP20, and CaO19.5847) were identified more recently. RNA-seq revealed IFF2/HYR3, DAL5, PSA31, and SIT1 were notably up-regulated, while multiple cell wall-associated genes (ALS1, MNN1, PUL1, DSE1, SCW11, PGA38, RBE1, FGR41, BGLI, GIT3, CEP3, and SAP2) were consistently down-regulated in rough morphotype C. auris. Discussion The rough phenotypic variation of C. auris is likely to be related to the structural and functional changes in cell wall proteins. This novel rough morphotype C. auris will provide a basis for further studies concerning the evolutionary characteristics of C. auris.
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Affiliation(s)
- Sufei Tian
- National Clinical Research Center for Laboratory Medicine, Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
| | - Jian Bing
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yunzhuo Chu
- National Clinical Research Center for Laboratory Medicine, Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
| | - Hailong Li
- National Clinical Research Center for Laboratory Medicine, Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
| | - Qihui Wang
- National Clinical Research Center for Laboratory Medicine, Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
| | - Shitong Cheng
- National Clinical Research Center for Laboratory Medicine, Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
| | - Jingjing Chen
- National Clinical Research Center for Laboratory Medicine, Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
| | - Hong Shang
- National Clinical Research Center for Laboratory Medicine, Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
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Yang L, Zhu H, Li M, Yu Q. The Tricalbin-Family Endoplasmic Reticulum-Plasma Membrane Tethering Proteins Attenuate ROS-Involved Caspofungin Sensitivity in Candida albicans. Microbiol Spectr 2022; 10:e0207922. [PMID: 36445092 PMCID: PMC9769562 DOI: 10.1128/spectrum.02079-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 11/07/2022] [Indexed: 12/02/2022] Open
Abstract
The endoplasmic reticulum-plasma membrane (ER-PM) contacts are one kind of important membrane contact structures in eukaryotic cells, which mediate material and message exchange between the ER and the PM. However, the specific types and functions of ER-PM tethering proteins are poorly understood in the human fungal pathogen Candida albicans. In this study, we observed that the two tricalbin-family proteins, i.e., Tcb1 and Tcb3, were colocalized with the ER-PM contacts in C. albicans. Deletion of the tricalbin-encoding genes TCB1 and TCB3 remarkably reduced ER-PM contacts, suggesting that tricalbins are ER-PM tethering proteins of C. albicans. Stress sensitivity assays showed that the TCB-deleted strains, including tcb1Δ/Δ, tcb3Δ/Δ, and tcb1Δ/Δ tcb3Δ/Δ, exhibited hypersensitivity to cell wall stress induced by caspofungin. Further investigation revealed that caspofungin induced drastic reactive oxygen species (ROS) accumulation in the mutants, which was attributed to enhanced oxidation of Ero1 in the ER lumen. Removal of intracellular ROS by the ROS scavenger vitamin C rescued the growth of the mutants under caspofungin treatment, indicating that Ero1 oxidation-related ROS accumulation was involved in caspofungin hypersensitivity of the mutants. Moreover, deletion of the TCB genes decreased secretion of extracellular aspartyl proteinases, reduced transport of the cell wall protein Hwp1 from the cytoplasm to the cell wall, and attenuated virulence of the fungal pathogen. This study sheds a light on the role of ER-PM tethering proteins in maintenance of cell wall integrity and virulence in fungal pathogens. IMPORTANCE The endoplasmic reticulum-plasma membrane contacts are important membrane contact structures in eukaryotic cells, functioning in material and message exchange between the ER and the PM. We observed that the two tricalbin-family endoplasmic reticulum-plasma membrane contact proteins are required for tolerance to caspofungin-induced cell wall stress in the pathogenic fungus Candida albicans. The tricalbin mutants exhibited hypersensitivity to cell wall stress induced by caspofungin. Further investigation revealed that Ero1 oxidation-related reactive species oxygen accumulation was involved in caspofungin hypersensitivity of the tricalbin mutants. Moreover, loss of tricalbins reduced secretion of extracellular aspartyl proteinases, decreased transport of the cell wall proteins from the cytoplasm to the cell wall, and attenuated virulence of the fungal pathogen. This study uncovers the role of ER-PM tethering proteins in sustaining protein secretion, maintenance of cell wall integrity and virulence in fungal pathogens.
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Affiliation(s)
- Li Yang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, People’s Republic of China
| | - Hangqi Zhu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, People’s Republic of China
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, People’s Republic of China
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, People’s Republic of China
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Synthesis of Dolichols in Candida albicans Is Co-Regulated with Elongation of Fatty Acids. Int J Mol Sci 2021; 23:ijms23010409. [PMID: 35008833 PMCID: PMC8745096 DOI: 10.3390/ijms23010409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/20/2021] [Accepted: 12/29/2021] [Indexed: 11/17/2022] Open
Abstract
Protein glycosylation requires dolichyl phosphate as a carbohydrate carrier. Dolichols are α-saturated polyprenols, and their saturation in S. cerevisiae is catalyzed by polyprenyl reductase Dfg10 together with some other unknown enzymes. The aim of this study was to identify such enzymes in Candida. The Dfg10 polyprenyl reductase from S. cerevisiae comprises a C-terminal 3-oxo-5-alpha-steroid 4-dehydrogenase domain. Alignment analysis revealed such a domain in two ORFs (orf19.209 and orf19.3293) from C. albicans, which were similar, respectively, to Dfg10 polyprenyl reductase and Tsc13 enoyl-transferase from S. cerevisiae. Deletion of orf19.209 in Candida impaired saturation of polyprenols. The Tsc13 homologue turned out not to be capable of saturating polyprenols, but limiting its expression reduce the cellular level of dolichols and polyprenols. This reduction was not due to a decreased expression of genes encoding cis-prenyltransferases from the dolichol branch but to a lower expression of genes encoding enzymes of the early stages of the mevalonate pathway. Despite the resulting lower consumption of acetyl-CoA, the sole precursor of the mevalonate pathway, it was not redirected towards fatty acid synthesis or elongation. Lowering the expression of TSC13 decreased the expression of the ACC1 gene encoding acetyl-CoA carboxylase, the key regulatory enzyme of fatty acid synthesis and elongation.
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Role of Protein Glycosylation in Interactions of Medically Relevant Fungi with the Host. J Fungi (Basel) 2021; 7:jof7100875. [PMID: 34682296 PMCID: PMC8541085 DOI: 10.3390/jof7100875] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 01/09/2023] Open
Abstract
Protein glycosylation is a highly conserved post-translational modification among organisms. It plays fundamental roles in many biological processes, ranging from protein trafficking and cell adhesion to host–pathogen interactions. According to the amino acid side chain atoms to which glycans are linked, protein glycosylation can be divided into two major categories: N-glycosylation and O-glycosylation. However, there are other types of modifications such as the addition of GPI to the C-terminal end of the protein. Besides the importance of glycoproteins in biological functions, they are a major component of the fungal cell wall and plasma membrane and contribute to pathogenicity, virulence, and recognition by the host immunity. Given that this structure is absent in host mammalian cells, it stands as an attractive target for developing selective compounds for the treatment of fungal infections. This review focuses on describing the relationship between protein glycosylation and the host–immune interaction in medically relevant fungal species.
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Inhibition of Dephosphorylation of Dolichyl Diphosphate Alters the Synthesis of Dolichol and Hinders Protein N-Glycosylation and Morphological Transitions in Candida albicans. Int J Mol Sci 2019; 20:ijms20205067. [PMID: 31614738 PMCID: PMC6829516 DOI: 10.3390/ijms20205067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/11/2019] [Accepted: 10/11/2019] [Indexed: 11/17/2022] Open
Abstract
The essential role of dolichyl phosphate (DolP) as a carbohydrate carrier during protein N-glycosylation is well established. The cellular pool of DolP is derived from de novo synthesis in the dolichol branch of the mevalonate pathway and from recycling of DolPP after each cycle of N-glycosylation, when the oligosaccharide is transferred from the lipid carrier to the protein and DolPP is released and then dephosphorylated. In Saccharomyces cerevisiae, the dephosphorylation of DolPP is known to be catalyzed by the Cwh8p protein. To establish the role of the Cwh8p orthologue in another distantly related yeast species, Candida albicans, we studied its mutant devoid of the CaCWH8 gene. A double Cacwh8∆/Cacwh8∆ strain was constructed by the URA-blaster method. As in S. cerevisiae, the mutant was impaired in DolPP recycling. This defect, however, was accompanied by an elevation of cis-prenyltransferase activity and higher de novo production of dolichols. Despite these compensatory changes, protein glycosylation, cell wall integrity, filamentous growth, and biofilm formation were impaired in the mutant. These results suggest that the defects are not due to the lack of DolP for the protein N-glycosylation but rather that the activity of oligosacharyltransferase could be inhibited by the excess DolPP accumulating in the mutant.
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Roles of VPH2 and VMA6 in localization of V-ATPase subunits, cell wall functions and filamentous development in Candida albicans. Fungal Genet Biol 2018. [PMID: 29522815 DOI: 10.1016/j.fgb.2018.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The vacuolar-type H+-ATPase (V-ATPase) is known to be associated with various cellular processes. Several V-ATPase subunits have been identified in C. albicans. However, there are still a few V-ATPase subunits and assembly factors that remain uncharacterized. In this study, we identified one of putative V-ATPase assembly factors, Vph2, and V0 subunit, Vma6, and explored their potential functions in C. albicans. Our results revealed that Vph2 and Vma6 were required for the correct distribution of V0 subunit Vph1 and V1 subunit Tfp1. Furthermore, Vph2 and Vma6 played an important role in endocytosis and vacuolar acidification. Disruption of VPH2 or VMA6 affected cell wall stress resistance and composition, accompanying induction of cell wall integrity (CWI) pathway. Besides, deletion of VPH2 or VMA6 led to weakened hyphal development in Spider medium that was not dependent on Hog1 activation. Moreover, the vph2Δ/Δ and vma6Δ/Δ mutants displayed attenuated virulence in a mouse model of systemic candidiasis. Taken together, our data indicated that Vph2 and Vma6 were essential for the proper localization of V-ATPase subunits, cell wall functions, filamentous growth and C. albicans pathogenesis, and provided the potential to better exploit V-ATPase-related proteins as antifungal targets.
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Wangsanut T, Ghosh AK, Metzger PG, Fonzi WA, Rolfes RJ. Grf10 and Bas1 Regulate Transcription of Adenylate and One-Carbon Biosynthesis Genes and Affect Virulence in the Human Fungal Pathogen Candida albicans. mSphere 2017; 2:e00161-17. [PMID: 28776040 PMCID: PMC5541157 DOI: 10.1128/msphere.00161-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 07/11/2017] [Indexed: 11/21/2022] Open
Abstract
Candida albicans is an opportunistic human fungal pathogen that causes superficial fungal infections and lethal systemic infections. To colonize and establish infections, C. albicans coordinates the expression of virulence and metabolic genes. Previous work showed that the homeodomain transcription factor Grf10 is required for formation of hyphae, a virulence factor. Here we report global gene expression analysis of a grf10Δ strain using a DNA microarray and identify genes for de novo adenylate biosynthesis (ADE genes), one-carbon metabolism, and a nucleoside permease (NUP). Upregulation of these genes in response to adenine limitation required both Grf10 and the myb protein Bas1, as shown by quantitative real-time PCR (qRT-PCR). Phenotypic analysis showed that both mutants exhibited growth defects when grown in the absence of adenine, and the doubling time was slower for the bas1Δ mutant. Bas1 is required for basal expression of these genes, whereas NUP expression is more dependent upon Grf10. Disruption of BAS1 led to only modest defects in hypha formation and weak attenuation of virulence in a systemic mouse model of infection, as opposed to the previously reported strong effects found in the grf10Δ mutant. Our data are consistent with a model in which Grf10 coordinates metabolic effects on nucleotide metabolism by interaction with Bas1 and indicate that AMP biosynthesis and its regulation are important for C. albicans growth and virulence. IMPORTANCECandida albicans is a commensal and a common constituent of the human microbiota; however, it can become pathogenic and cause infections in both immunocompetent and immunocompromised people. C. albicans exhibits remarkable metabolic versatility as it can colonize multiple body sites as a commensal or pathogen. Understanding how C. albicans adapts metabolically to each ecological niche is essential for developing novel therapeutic approaches. Purine metabolism has been targeted pharmaceutically in several diseases; however, the regulation of this pathway has not been fully elucidated in C. albicans. Here, we report how C. albicans controls the AMP de novo biosynthesis pathway in response to purine availability. We show that the lack of the transcription factors Grf10 and Bas1 leads to purine metabolic dysfunction, and this dysfunction affects the ability of C. albicans to establish infections.
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Affiliation(s)
| | - Anup K. Ghosh
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Peter G. Metzger
- Department of Biology, Georgetown University, Washington, DC, USA
| | - William A. Fonzi
- Department of Microbiology and Immunology, Georgetown University, Washington, DC, USA
| | - Ronda J. Rolfes
- Department of Biology, Georgetown University, Washington, DC, USA
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Niewiadomska M, Janik A, Perlińska-Lenart U, Piłsyk S, Palamarczyk G, Kruszewska JS. The role of Alg13 N-acetylglucosaminyl transferase in the expression of pathogenic features of Candida albicans. Biochim Biophys Acta Gen Subj 2017; 1861:789-801. [DOI: 10.1016/j.bbagen.2017.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 01/16/2017] [Accepted: 01/21/2017] [Indexed: 01/09/2023]
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Juchimiuk M, Kruszewska J, Palamarczyk G. Dolichol phosphate mannose synthase from the pathogenic yeast Candida albicans is a multimeric enzyme. Biochim Biophys Acta Gen Subj 2015; 1850:2265-75. [DOI: 10.1016/j.bbagen.2015.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 08/12/2015] [Indexed: 11/29/2022]
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Short-chain polyisoprenoids in the yeast Saccharomyces cerevisiae - New companions of the old guys. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1296-303. [PMID: 26143379 DOI: 10.1016/j.bbalip.2015.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 06/16/2015] [Accepted: 06/25/2015] [Indexed: 11/20/2022]
Abstract
Dolichols are, among others, obligatory cofactors of protein glycosylation in eukaryotic cells. It is well known that yeast cells accumulate a family of dolichols with Dol-15/16 dominating while upon certain physiological conditions a second family with Dol-21 dominating is noted. In this report we identified the presence of additional short-chain length polyprenols - all-trans Pren-7 in three yeast strains (SS328, BY4741 and L5366), Pren-7 was accompanied by traces of putative Pren-6 and -8. Moreover, in two of these strains a single polyprenol mainly-cis-Pren-11 was synthesized at the stationary phase of growth. Identity of polyprenols was confirmed by HR-HPLC/MS, NMR and metabolic labeling. Additionally, simvastatin inhibited their biosynthesis.
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