1
|
Chen Y, Wang X, Li J, Wang Z, Song T, Lai X, Zhang G, Ruan W. The effects of different biochars on Caenorhabditis elegans and the underlying transcriptomic mechanisms. PLoS One 2023; 18:e0284348. [PMID: 37738276 PMCID: PMC10516431 DOI: 10.1371/journal.pone.0284348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/29/2023] [Indexed: 09/24/2023] Open
Abstract
Different biochars have diverse properties, with ambiguous effects on soil nematodes. This study investigated how aspen sawdust (ABC), bamboo powder (BBC), maize straw (MBC) and peanut-shell biochars (PBC) affected Caenorhabditis elegans via culture assays and RNA-seq analysis. The results showed that biochars derived from different agricultural materials varied significantly in physicochemical properties, and PBC produced more volatile organic compounds (VOCs) to attract C. elegans than ABC, BBC and MBC. Moreover, worms in ABC experienced the worst outcomes, while worms in PBC experienced milder impacts. Nematode body length decreased to 724.6 μm, 784.0 μm and 799.7 μm on average in ABC, BBC and MBC, respectively, compared to the control (1052 μm) and PBC treatments (960 μm). The brood size in ABC, MBC, BBC and PBC decreased 41.1%, 39.4%, 39.2% and 19.1% compared to the control, respectively. Furthermore, the molecular mechanisms of biochar-induced developmental effects on C. elegans were explored. Although several differentially expressed genes (DEGs) were different among the four biochars, worm phenotypic changes were mainly related to col genes (col-129; col-140; col-40; col-184), bli-6, sqt-3, perm-2/4, cdk-8, daf-16 and sod-1/2/5, which are associated with cuticle collagen synthesis, eggshell formation in postembryonic growth and rhythmic processes. Our study suggests that different properties of biochars could be crucial to soil nematodes, as well as the worms' biochemical changes are important for the health in agriculture soil.
Collapse
Affiliation(s)
- Yixuan Chen
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, China
- College of Agronomy, Shenyang Agricultural University, Shenyang, China
| | - Xinrui Wang
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, China
| | - Jie Li
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, China
| | - Zhiwen Wang
- College of Resources and Environment, Northeast Agricultural University, Harbin, China
| | - Tingting Song
- Institute of Environment and Sustainable Development in Agriculture, CAAS, Beijing, China
| | - Xin Lai
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, China
| | - Guilong Zhang
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, China
| | - Weibin Ruan
- College of Life Sciences, Nankai University, Tianjin, China
| |
Collapse
|
2
|
Li J, Chen Y, Zhang G, Ruan W, Shan S, Lai X, Yang D, Yu Z. Integration of behavioural tests and transcriptome sequencing of C. elegans reveals how the nematode responds to peanut shell biochar amendment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:136024. [PMID: 31972909 DOI: 10.1016/j.scitotenv.2019.136024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 11/05/2019] [Accepted: 12/07/2019] [Indexed: 06/10/2023]
Abstract
Biochars have drawn wide attention as adsorbents, carbon sequesters and soil re-mediators. However, these substances are ambiguous regarding their effects on the motility, phenotypic changes and potential adaptative mechanisms of soil organisms. This study investigated how peanut shell biochar (PBC) affects the C. elegans model via a one-choice selection test and RNA-seq analysis. The results showed that C. elegans were able to select either PBC or a water control, and a clear preference for PBC was observed after 48 h of exposure, with the chemotaxis index (CI) reaching approximately 1.0. The nematode preferences for PBC vs sterile PBC/graphite were not significant, which demonstrated that initial microorganisms and appearances were not the reasons for the worms' selection, but the selection behaviour was instead determined by volatile odours. The treatments also showed that biochar amendment significantly decreased the body length, brood size and superoxide dismutase (SOD) activity of C. elegans to 960.20 ± 15.23 μm, 173.22 ± 4.56, 165.81 ± 3.82 U/mL SOD, respectively. Then, a possible molecular mechanism of PBC-induced developmental and reproductive effects on C. elegans was explored. Differential gene expression analysis was performed, and 1625 genes (1425 up- and 225 downregulated genes) were regulated in response to PBC treatment. The top 20 regulated genes were col genes (col-129; col-81; col-139; col-71), bli-6, perm-4 and his-24, which indicated that cuticle collagen synthesis, eggshell formation and/or heterochromatin in postembryonic growth may be disrupted following exposure to PBC. Therefore, our study suggested that quality standards be used to test nematode preferences and responses to biochar amendment, with the aim of safe application in soils, seedling substrates or fertilizers.
Collapse
Affiliation(s)
- Jie Li
- Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
| | - Yixuan Chen
- Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China; College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China.
| | - Guilong Zhang
- Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
| | - Weibin Ruan
- College of Life Sciences, Nankai University, Tianjin 30071, China.
| | - Shaojie Shan
- College of Life Sciences, Nankai University, Tianjin 30071, China.
| | - Xin Lai
- Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
| | - Dianlin Yang
- Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, China.
| | - Zhiguo Yu
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
| |
Collapse
|
3
|
Starnes DL, Lichtenberg SS, Unrine JM, Starnes CP, Oostveen EK, Lowry GV, Bertsch PM, Tsyusko OV. Distinct transcriptomic responses of Caenorhabditis elegans to pristine and sulfidized silver nanoparticles. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 213:314-321. [PMID: 26925754 DOI: 10.1016/j.envpol.2016.01.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/23/2015] [Accepted: 01/07/2016] [Indexed: 06/05/2023]
Abstract
Manufactured nanoparticles (MNP) rapidly undergo aging processes once released from products. Silver sulfide (Ag2S) is the major transformation product formed during the wastewater treatment process for Ag-MNP. We examined toxicogenomic responses of pristine Ag-MNP, sulfidized Ag-MNP (sAg-MNP), and AgNO3 to a model soil organism, Caenorhabditis elegans. Transcriptomic profiling of nematodes which were exposed at the EC30 for reproduction for AgNO3, Ag-MNP, and sAg-MNP resulted in 571 differentially expressed genes. We independently verified expression of 4 genes (numr-1, rol-8, col-158, and grl-20) using qRT-PCR. Only 11% of differentially expressed genes were common among the three treatments. Gene ontology enrichment analysis also revealed that Ag-MNP and sAg-MNP had distinct toxicity mechanisms and did not share any of the biological processes. The processes most affected by Ag-MNP relate to metabolism, while those processes most affected by sAg-MNP relate to molting and the cuticle, and the most impacted processes for AgNO3 exposed nematodes was stress related. Additionally, as observed from qRT-PCR and mutant experiments, the responses to sAg-MNP were distinct from AgNO3 while some of the effects of pristine MNP were similar to AgNO3, suggesting that effects from Ag-MNP is partially due to dissolved silver ions.
Collapse
Affiliation(s)
- Daniel L Starnes
- Department of Plant and Soil Sciences, University of Kentucky, 1100 South Limestone Street, Lexington, KY 40546, United States
| | - Stuart S Lichtenberg
- Department of Plant and Soil Sciences, University of Kentucky, 1100 South Limestone Street, Lexington, KY 40546, United States; Center for Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Duke University, Durham, NC 27708-0287, United States
| | - Jason M Unrine
- Department of Plant and Soil Sciences, University of Kentucky, 1100 South Limestone Street, Lexington, KY 40546, United States; Center for Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Duke University, Durham, NC 27708-0287, United States
| | - Catherine P Starnes
- Department of Statistics, University of Kentucky, 725 Rose Street, MDS Building 305, Lexington, KY 40536, United States
| | - Emily K Oostveen
- Department of Plant and Soil Sciences, University of Kentucky, 1100 South Limestone Street, Lexington, KY 40546, United States
| | - Gregory V Lowry
- Center for Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Duke University, Durham, NC 27708-0287, United States; Department of Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States
| | - Paul M Bertsch
- Department of Plant and Soil Sciences, University of Kentucky, 1100 South Limestone Street, Lexington, KY 40546, United States; Center for Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Duke University, Durham, NC 27708-0287, United States; Division of Land and Water, CSIRO, Ecosciences Precinct, Brisbane, QLD, Australia
| | - Olga V Tsyusko
- Department of Plant and Soil Sciences, University of Kentucky, 1100 South Limestone Street, Lexington, KY 40546, United States; Center for Environmental Implications of NanoTechnology (CEINT), P.O. Box 90287, Duke University, Durham, NC 27708-0287, United States.
| |
Collapse
|
4
|
Use of an activated beta-catenin to identify Wnt pathway target genes in caenorhabditis elegans, including a subset of collagen genes expressed in late larval development. G3-GENES GENOMES GENETICS 2014; 4:733-47. [PMID: 24569038 PMCID: PMC4059243 DOI: 10.1534/g3.113.009522] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The Wnt signaling pathway plays a fundamental role during metazoan development, where it regulates diverse processes, including cell fate specification, cell migration, and stem cell renewal. Activation of the beta-catenin-dependent/canonical Wnt pathway up-regulates expression of Wnt target genes to mediate a cellular response. In the nematode Caenorhabditis elegans, a canonical Wnt signaling pathway regulates several processes during larval development; however, few target genes of this pathway have been identified. To address this deficit, we used a novel approach of conditionally activated Wnt signaling during a defined stage of larval life by overexpressing an activated beta-catenin protein, then used microarray analysis to identify genes showing altered expression compared with control animals. We identified 166 differentially expressed genes, of which 104 were up-regulated. A subset of the up-regulated genes was shown to have altered expression in mutants with decreased or increased Wnt signaling; we consider these genes to be bona fide C. elegans Wnt pathway targets. Among these was a group of six genes, including the cuticular collagen genes, bli-1 col-38, col-49, and col-71. These genes show a peak of expression in the mid L4 stage during normal development, suggesting a role in adult cuticle formation. Consistent with this finding, reduction of function for several of the genes causes phenotypes suggestive of defects in cuticle function or integrity. Therefore, this work has identified a large number of putative Wnt pathway target genes during larval life, including a small subset of Wnt-regulated collagen genes that may function in synthesis of the adult cuticle.
Collapse
|
5
|
Merris M, Wang T, Soteropoulos P, Lenard J. Differential gene expression of Caenorhabditis elegans grown on unmethylated sterols or 4α-methylsterols. J Lipid Res 2007; 48:1159-66. [PMID: 17277379 DOI: 10.1194/jlr.m600552-jlr200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcriptional profiles of Caenorhabditis elegans grown on unmethylated sterols (desMSs) or on 4alpha-methylsterols (4MSs) were compared using microarrays. Thirty-four genes were upregulated and 2 were downregulated>2-fold by growth on 4MSs, including 13 cuticle collagen (col) genes, 1 cuticulin gene (cut-1), 2 groundhog-like (grl) genes, and 1 groundhog gene (grd-4); col-36 and grl-20 were increased 12- and 19-fold, respectively. Fifteen of these 17 genes have been assigned to metabolic mountain 17, suggesting coordinate 4MS-mediated regulation of expression. Quantitative RT-PCR was performed on 27-51 h old animals grown on cholesterol (a desMS) or lophenol (a 4MS). col-36 and grl-20 showed similar cyclic peaks of expression in cholesterol and similar alterations in lophenol, suggesting coregulation. Of six additional grl genes, only grl-3 was upregulated on lophenol; the rest were downregulated. Cyclicity of expression was lost or altered in all six. Nuclear receptor genes nhr-23, nhr-25, nhr-41, and daf-12 all showed cyclic expression in cholesterol and significant downregulation in lophenol by RT-PCR. Expression of the insulin-like receptor daf-2 was lower in lophenol, whereas that of its major downstream target daf-16 was higher. Thus, major changes in gene expression accompany growth on 4MSs, but with surprisingly little effect on normal growth and development.
Collapse
Affiliation(s)
- Mark Merris
- Department of Physiology and Biophysics, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | | | | | | |
Collapse
|
6
|
Regulation of signaling genes by TGFbeta during entry into dauer diapause in C. elegans. BMC DEVELOPMENTAL BIOLOGY 2004; 4:11. [PMID: 15380030 PMCID: PMC524168 DOI: 10.1186/1471-213x-4-11] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Accepted: 09/20/2004] [Indexed: 11/18/2022]
Abstract
Background When resources are scant, C. elegans larvae arrest as long-lived dauers under the control of insulin/IGF- and TGFβ-related signaling pathways. However, critical questions remain regarding the regulation of this developmental event. How do three dozen insulin-like proteins regulate one tyrosine kinase receptor to control complex events in dauer, metabolism and aging? How are signals from the TGFβ and insulin/IGF pathways integrated? What gene expression programs do these pathways regulate, and how do they control complex downstream events? Results We have identified genes that show different levels of expression in a comparison of wild-type L2 or L3 larvae (non-dauer) to TGFβ mutants at similar developmental stages undergoing dauer formation. Many insulin/IGF pathway and other known dauer regulatory genes have changes in expression that suggest strong positive feedback by the TGFβ pathway. In addition, many insulin-like ligand and novel genes with similarity to the extracellular domain of insulin/IGF receptors have altered expression. We have identified a large group of regulated genes with putative binding sites for the FOXO transcription factor, DAF-16. Genes with DAF-16 sites upstream of the transcription start site tend to be upregulated, whereas genes with DAF-16 sites downstream of the coding region tend to be downregulated. Finally, we also see strong regulation of many novel hedgehog- and patched-related genes, hormone biosynthetic genes, cell cycle genes, and other regulatory genes. Conclusions The feedback regulation of insulin/IGF pathway and other dauer genes that we observe would be predicted to amplify signals from the TGFβ pathway; this amplification may serve to ensure a decisive choice between "dauer" and "non-dauer", even if environmental cues are ambiguous. Up and down regulation of insulin-like ligands and novel genes with similarity to the extracellular domain of insulin/IGF receptors suggests opposing roles for several members of these large gene families. Unlike in adults, most genes with putative DAF-16 binding sites are upregulated during dauer entry, suggesting that DAF-16 has different activity in dauer versus adult metabolism and aging. However, our observation that the position of putative DAF-16 binding sites is correlated with the direction of regulation suggests a novel method of achieving gene-specific regulation from a single pathway. We see evidence of TGFβ-mediated regulation of several other classes of regulatory genes, and we discuss possible functions of these genes in dauer formation.
Collapse
|
7
|
Muriel JM, Brannan M, Taylor K, Johnstone IL, Lithgow GJ, Tuckwell D. M142.2 (cut-6), a novel Caenorhabditis elegans matrix gene important for dauer body shape. Dev Biol 2003; 260:339-51. [PMID: 12921736 DOI: 10.1016/s0012-1606(03)00237-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The cuticle of the nematode Caenorhabditis elegans is a collagenous extracellular matrix which forms the exoskeleton and defines the shape of the worm. We have characterized the C. elegans gene M142.2, and we show that this is a developmentally regulated gene important for cuticle structure. Transgenic worms expressing M142.2 promoter fused to green fluorescent protein showed that M142.2 is expressed in late embryos and L2d predauers, in the hypodermal cells which synthesize the cuticle. The same temporal pattern was seen by RT-PCR using RNA purified from specific developmental stages. A recombinant fragment of M142.2 was expressed in Escherichia coli and used to raise an antiserum. Immunohistochemistry using the antiserum localized M142.2 to the periphery of the alae of L1 and dauers, forming two longitudinal ribbons over the hypodermal cells. Loss-of-function of M142.2 by RNAi resulted in a novel phenotype: dumpy dauers which lacked alae. M142.2 therefore plays a major role in the assembly of the alae and the morphology of the dauer cuticle; because of its similarity to the other cut genes of the cuticle, we have named the gene cut-6.
Collapse
Affiliation(s)
- Joaquin M Muriel
- Department of Cell and Molecular Biology, Northwestern University Medical School, 303 E Chicago Ave, Chicago, IL 60611, USA
| | | | | | | | | | | |
Collapse
|
8
|
Gray LJ, Curtis RH, Jones JT. Characterisation of a collagen gene subfamily from the potato cyst nematode Globodera pallida. Gene 2001; 263:67-75. [PMID: 11223244 DOI: 10.1016/s0378-1119(00)00558-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have isolated two full-length genomic DNA sequences, which encode the cuticle collagen proteins GP-COL-1 and GP-COL-2, from the potato cyst nematode Globodera pallida. A third, partial collagen gene ORF termed gp-col-t(t=truncated) has also been isolated and appears to represent an unexpressed pseudogene. The gp-col-1 and gp-col-2 genes both contain three short (<97 bp) introns which disrupt coding regions predicted to specify proteins with molecular weights of 33 and 32.7 kDa respectively. All three sequences show high similarity to each other and to the previously isolated G. pallida cDNA clone gp-col-8. The conserved pattern of cysteine residues and non-(Gly-X-Y)(n) region sequence similarity observed in all four G. pallida genes suggests that these molecules form part of the same subfamily of collagens. Southern analysis indicates that this subfamily is likely to contain further members. The G. pallida collagen sequences show striking similarity to twelve genes from Caenorhabditis elegans which collectively represent the recently classified Group 1a collagen subfamily. No data exists on the function of this subfamily in C. elegans. gp-col-1 and gp-col-2 are developmentally regulated with transcripts of both genes detected in adult virgin and gravid females but not in pre-parasitic second stage juveniles. A similar expression pattern is observed for the Group 1a collagen lemmi 5 from Meloidogyne incognita perhaps indicating a generic link between subfamily and function during the various changes in cuticular structure which accompany nematode growth and reproduction. Immunochemical studies indicate that the GP-COL-1 protein is specifically located in the hypodermis of G. pallida adult females.
Collapse
Affiliation(s)
- L J Gray
- Unit of Mycology, Bacteriology and Nematology, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK.
| | | | | |
Collapse
|
9
|
Gilleard JS, Barry JD, Johnstone IL. cis regulatory requirements for hypodermal cell-specific expression of the Caenorhabditis elegans cuticle collagen gene dpy-7. Mol Cell Biol 1997; 17:2301-11. [PMID: 9121480 PMCID: PMC232079 DOI: 10.1128/mcb.17.4.2301] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The Caenorhabditis elegans cuticle collagens are encoded by a multigene family of between 50 and 100 members and are the major component of the nematode cuticular exoskeleton. They are synthesized in the hypodermis prior to secretion and incorporation into the cuticle and exhibit complex patterns of spatial and temporal expression. We have investigated the cis regulatory requirements for tissue- and stage-specific expression of the cuticle collagen gene dpy-7 and have identified a compact regulatory element which is sufficient to specify hypodermal cell reporter gene expression. This element appears to be a true tissue-specific promoter element, since it encompasses the dpy-7 transcription initiation sites and functions in an orientation-dependent manner. We have also shown, by interspecies transformation experiments, that the dpy-7 cis regulatory elements are functionally conserved between C. elegans and C. briggsae, and comparative sequence analysis supports the importance of the regulatory sequence that we have identified by reporter gene analysis. All of our data suggest that the spatial expression of the dpy-7 cuticle collagen gene is established essentially by a small tissue-specific promoter element and does not require upstream activator or repressor elements. In addition, we have found the DPY-7 polypeptide is very highly conserved between the two species and that the C. briggsae polypeptide can function appropriately within the C. elegans cuticle. This finding suggests a remarkably high level of conservation of individual cuticle components, and their interactions, between these two nematode species.
Collapse
Affiliation(s)
- J S Gilleard
- Wellcome Unit of Molecular Parasitology, Anderson College, University of Glasgow, United Kingdom.
| | | | | |
Collapse
|
10
|
Scott AL, Yenbutr P, Eisinger SW, Raghavan N. Molecular cloning of the cuticular collagen gene Bmcol-2 from Brugia malayi. Mol Biochem Parasitol 1995; 70:221-5. [PMID: 7637708 DOI: 10.1016/0166-6851(95)00017-u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- A L Scott
- Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Hygiene and Public Health, Baltimore, MD 21205, USA
| | | | | | | |
Collapse
|
11
|
In vitro mutagenesis of Caenorhabditis elegans cuticle collagens identifies a potential subtilisin-like protease cleavage site and demonstrates that carboxyl domain disulfide bonding is required for normal function but not assembly. Mol Cell Biol 1994. [PMID: 8139571 DOI: 10.1128/mcb.14.4.2722] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The importance of conserved amino acids in the amino and carboxyl non-Gly-X-Y domains of Caenorhabditis elegans cuticle collagens was examined by analyzing site-directed mutations of the sqt-1 and rol-6 collagen genes in transgenic animals. Altered collagen genes on transgenic arrays were shown to produce appropriate phenotypes by injecting in vivo cloned mutant alleles. Equivalent alterations in sqt-1 and rol-6 generally produced the same phenotypes, indicating that conserved amino acids in these two collagens have similar functions. Serine substitutions for either of two conserved carboxyl domain cysteines produced LRol phenotypes. Substitution for both cysteines in sqt-1 also resulted in an LRol phenotype, demonstrating that disulfide bonding is important for normal function but not required for assembly. Arg-1 or Arg-4 to Cys mutations in homology block A (HBA; consensus, 1-RXRRQ-5; in the amino non-Gly-X-Y domain) caused RRol phenotypes, while the same alteration at Arg-3 had no effect, indicating that Arg-3 is functionally different from Arg-1 and Arg-4. Substitutions of Arg-4 with Ser, Leu, or Glu also produced the RRol phenotype, while Lys substitutions for Arg-1 or Arg-4 did not generate any abnormal phenotypes. His substitutions for Arg-1 or Arg-4 caused somewhat less severe RRol phenotypes. Therefore, strong positively charged residues, Arg or Lys, are required at positions 1 and 4 for normal function. The conserved pattern of arginines in HBA matches the cleavage sites of the subtilisin-like endoproteinases. HBA may be a cleavage site for a subtilisin-like protease, and cleavage may be important for cuticle collagen processing.
Collapse
|
12
|
Yang J, Kramer JM. In vitro mutagenesis of Caenorhabditis elegans cuticle collagens identifies a potential subtilisin-like protease cleavage site and demonstrates that carboxyl domain disulfide bonding is required for normal function but not assembly. Mol Cell Biol 1994; 14:2722-30. [PMID: 8139571 PMCID: PMC358638 DOI: 10.1128/mcb.14.4.2722-2730.1994] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The importance of conserved amino acids in the amino and carboxyl non-Gly-X-Y domains of Caenorhabditis elegans cuticle collagens was examined by analyzing site-directed mutations of the sqt-1 and rol-6 collagen genes in transgenic animals. Altered collagen genes on transgenic arrays were shown to produce appropriate phenotypes by injecting in vivo cloned mutant alleles. Equivalent alterations in sqt-1 and rol-6 generally produced the same phenotypes, indicating that conserved amino acids in these two collagens have similar functions. Serine substitutions for either of two conserved carboxyl domain cysteines produced LRol phenotypes. Substitution for both cysteines in sqt-1 also resulted in an LRol phenotype, demonstrating that disulfide bonding is important for normal function but not required for assembly. Arg-1 or Arg-4 to Cys mutations in homology block A (HBA; consensus, 1-RXRRQ-5; in the amino non-Gly-X-Y domain) caused RRol phenotypes, while the same alteration at Arg-3 had no effect, indicating that Arg-3 is functionally different from Arg-1 and Arg-4. Substitutions of Arg-4 with Ser, Leu, or Glu also produced the RRol phenotype, while Lys substitutions for Arg-1 or Arg-4 did not generate any abnormal phenotypes. His substitutions for Arg-1 or Arg-4 caused somewhat less severe RRol phenotypes. Therefore, strong positively charged residues, Arg or Lys, are required at positions 1 and 4 for normal function. The conserved pattern of arginines in HBA matches the cleavage sites of the subtilisin-like endoproteinases. HBA may be a cleavage site for a subtilisin-like protease, and cleavage may be important for cuticle collagen processing.
Collapse
Affiliation(s)
- J Yang
- Department of Cell, Molecular and Structural Biology, Northwestern University Medical School, Chicago, Illinois 60611
| | | |
Collapse
|