scholarly journals An Update on the Metabolic Roles of Carbonic Anhydrases in a Model Alga Chlamydomonas reinhardtii

2018 ◽  
Author(s):  
Ashok Aspatwar ◽  
Susanna Haapanen ◽  
Seppo Parkkila
Keyword(s):  
Gene Family ◽  
Chlamydomonas Reinhardtii ◽  
Gene Families ◽  
Carbonic Anhydrases ◽  
Unicellular Alga ◽  
Photosynthetic Organisms ◽  
Basic Reaction ◽  
Multiple Copies ◽  
Living Organisms ◽  
Reversible Hydration

Carbonic anhydrases (CAs) are metalloenzymes that are omnipresent in nature. The CAs catalyze the basic reaction of reversible hydration of CO2 to HCO3− and H+ in all living organisms. Photosynthetic organisms contain six evolutionarily different classes of CAs, namely, α-CAs, β-CAs, γ-CAs, δ-CAs, ζ-CAs, and θ-CAs. Many of the photosynthetic organisms contain multiple isoforms of each CA family. Model alga, Chlamydomonas reinhardtii contains fifteen CAs belonging to three different CA gene families. Out of the fifteen CAs, three belong to α-CA gene family, nine to β-CA gene family, and three are γ-CAs. The multiple copies of the CAs in each gene family may be due to gene duplications within the particular CA gene family. The CAs of Chlamydomonas reinhardtii are localized in different subcellular compartments of this unicellular alga. The presence of a large number of CAs and their diverse subcellular localization within a single cell suggests the importance of these enzymes in metabolic and biochemical roles they perform in this unicellular alga. In the present review, we update the information on molecular biology of all the fifteen CAs and their metabolic and biochemical roles in Chlamydomonas reinhardtii. We also present a hypothetical model showing the known functions of CAs and predicting the functions of CAs for which precise metabolic roles are yet to be discovered.

The carbonic anhydrase gene families of Chlamydomonas reinhardtii

2005 ◽  
Vol 83 (7) ◽  
pp. 780-795 ◽  
Author(s):  
Mautusi Mitra ◽  
Catherine B Mason ◽  
Ying Xiao ◽  
Ruby A Ynalvez ◽  
Scott M Lato ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Chlamydomonas Reinhardtii ◽  
Gene Families ◽  
Carbonic Anhydrases ◽  
Photosynthetic Organisms ◽  
Surrounding Environment ◽  
Concentrating Mechanism ◽  
Chloroplast Stroma ◽  
Carbonic Anhydrase Gene

Carbonic anhydrases (CAs) are zinc-containing metalloenzymes that catalyze the reversible interconversion of CO2 and HCO3–. Aquatic photosynthetic organisms have evolved different forms of CO2-concentrating mechanisms to aid Rubisco in capturing CO2 from the surrounding environment. One aspect of all CO2-concentrating mechanisms is the critical roles played by various specially localized extracellular and intracellular CAs. There are three evolutionarily unrelated CA families designated α-, β-, and γ-CA. In the green alga, Chlamydomonas reinhardtii Dangeard, eight CAs have now been identified, including three α-CAs and five β-CAs. In addition, C. reinhardtii has another CA-like gene, Glp1 that is similar to known γ-CAs. To characterize these different CA isoforms, some of the CA genes have been overexpressed to determine whether the proteins have CA activity and to generate antibodies for in vivo immunolocalization. The CA proteins Cah3, Cah6, and Cah8, and the γ-CA-like protein, Glp1, have been overexpressed. Cah3, Cah6, and Cah8 have CA activity, but Glp1 does not. At least two of these proteins, Cah3 and Cah6, are localized to the chloroplast. Using immunolocalization and sequence analyses, we have determined that Cah6 is located to the chloroplast stroma and confirmed that Cah3 is localized to the chloroplast thylakoid lumen. Activity assays show that Cah3 is 100 times more sensitive to sulfonamides than Cah6. We present a model on how these two chloroplast CAs might participate in the CO2-concentrating mechanism of C. reinhardtii. Key words: carbonic anhydrase, CO2-concentrating mechanism, Chlamydomonas, immunolocalization.

scholarly journals Evidence that the E4 and FE4 esterase genes responsible for insecticide resistance in the aphid Myzus persicae (Sulzer) are part of a gene family

1998 ◽  
Vol 330 (1) ◽  
pp. 169-173 ◽  
Author(s):  
M. Linda FIELD ◽  
L. Alan DEVONSHIRE
Keyword(s):  
Insecticide Resistance ◽  
Gene Family ◽  
Myzus Persicae ◽  
Cpg Island ◽  
Gene Families ◽  
Duplication Event ◽  
Potato Aphid ◽  
Insecticide Exposure ◽  
Genes Encoding ◽  
Multiple Copies

The amplification of genes encoding the esterases E4 and FE4 is a widespread mechanism of insecticide resistance in the peach-potato aphid, Myzus persicae (Sulzer). We present evidence that in susceptible aphids the two genes are adjacent to each other in a head-to-tail arrangement with E4 upstream of FE4 and with approx. 19 kb of intervening sequence. There are also at least two other closely related sequences which might come from other members of an esterase gene family, in line with reports of other insect gene families encoding detoxifying enzymes. The close identity between E4 and FE4 genes indicates a recent duplication and divergence. The subsequent amplifications giving multiple copies of either E4 or FE4 must have involved two separate events, each probably occurring once and then being selected by insecticide exposure and spread by migration. The cloning of sequences upstream of the FE4 gene suggest, by comparison with E4, that the two genes are regulated in different ways. FE4 has sequences corresponding to a conventional promoter (TATA box and CAP site) that are not present in E4; on the other hand, FE4 lacks the CpG island present 5ʹ of E4 genes that may control expression through changes in DNA methylation. The differences are likely to have occurred by the duplication event that gave rise to E4 and FE4 leading to different 5ʹ sequences.

scholarly journals Effect of Sulfonamides and Their Structurally Related Derivatives on the Activity of ι-Carbonic Anhydrase from Burkholderia territorii

2021 ◽  
Vol 22 (2) ◽  
pp. 571
Author(s):  
Viviana De Luca ◽  
Andrea Petreni ◽  
Alessio Nocentini ◽  
Andrea Scaloni ◽  
Claudiu T. Supuran ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Selective Inhibition ◽  
Extensive Study ◽  
Protein Isoforms ◽  
Carbonic Anhydrases ◽  
Physiological Processes ◽  
Microbial Survival ◽  
Reversible Hydration

Carbonic anhydrases (CAs) are essential metalloenzymes in nature, catalyzing the carbon dioxide reversible hydration into bicarbonate and proton. In humans, breathing and many other critical physiological processes depend on this enzymatic activity. The CA superfamily function and inhibition in pathogenic bacteria has recently been the object of significant advances, being demonstrated to affect microbial survival/virulence. Targeting bacterial CAs may thus be a valid alternative to expand the pharmacological arsenal against the emergence of widespread antibiotic resistance. Here, we report an extensive study on the inhibition profile of the recently discovered ι-CA class present in some bacteria, including Burkholderia territorii, namely BteCAι, using substituted benzene-sulfonamides and clinically licensed sulfonamide-, sulfamate- and sulfamide-type drugs. The BteCAι inhibition profile showed: (i) several benzene-sulfonamides with an inhibition constant lower than 100 nM; (ii) a different behavior with respect to other α, β and γ-CAs; (iii) clinically used drugs having a micromolar affinity. This prototype study contributes to the initial recognition of compounds which efficiently and selectively inhibit a bacterial member of the ι-CA class, for which such a selective inhibition with respect to other protein isoforms present in the host is highly desired and may contribute to the development of novel antimicrobials.

scholarly journals Isolation and Characterization Of Rice R Genes: Evidence for Distinct Evolutionary Paths in Rice and Maize

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 1021-1031 ◽  
Author(s):  
Jianping Hu ◽  
Beth Anderson ◽  
Susan R Wessler
Keyword(s):  
Gene Family ◽  
Gene Families ◽  
Chromosome 1 ◽  
R Gene ◽  
R Genes ◽  
Helix Loop Helix ◽  
Isolation And Characterization ◽  
Undetermined Function ◽  
Evolutionary Paths

Abstract R and B genes and their homologues encode basic helix-loop-helix (bHLH) transcriptional activators that regulate the anthocyanin biosynthetic pathway in flowering plants. In maize, R/B genes comprise a very small gene family whose organization reflects the unique evolutionary history and genome architecture of maize. To know whether the organization of the R gene family could provide information about the origins of the distantly related grass rice, we characterized members of the R gene family from rice Oryza sativa. Despite being a true diploid, O. sativa has at least two R genes. An active homologue (Ra) with extensive homology with other R genes is located at a position on chromosome 4 previously shown to be in synteny with regions of maize chromosomes 2 and 10 that contain the B and R loci, respectively. A second rice R gene (Rb) of undetermined function was identified on chromosome 1 and found to be present only in rice species with AA genomes. All non-AA species have but one R gene that is Ra-like. These data suggest that the common ancestor shared by maize and rice had a single R gene and that the small R gene families of grasses have arisen recently and independently.

scholarly journals Expression of a gene duplication encoding conserved sperm tail proteins is translationally regulated in Drosophila melanogaster.

1993 ◽  
Vol 13 (3) ◽  
pp. 1708-1718 ◽  
Author(s):  
M Schäfer ◽  
D Börsch ◽  
A Hülster ◽  
U Schäfer
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Family ◽  
Translational Control ◽  
Germ Line ◽  
Gene Families ◽  
Homologous Gene ◽  
Male Sterile ◽  
Sperm Tail ◽  
Repetitive Motif ◽  
Carboxy Terminal

We have analyzed a locus of Drosophila melanogaster located at 98C on chromosome 3, which contains two tandemly arranged genes, named Mst98Ca and Mst98Cb. They are two additional members of the Mst(3)CGP gene family by three criteria. (i) Both genes are exclusively transcribed in the male germ line. (ii) Both transcripts encode a protein with a high proportion of the repetitive motif Cys-Gly-Pro. (iii) Their expression is translationally controlled; while transcripts can be detected in diploid stages of spermatogenesis, association with polysomes can be shown only in haploid stages of sperm development. The genes differ markedly from the other members of the gene family in structure; they do not contain introns, they are of much larger size, and they have the Cys-Gly-Pro motifs clustered at the carboxy-terminal end of the encoded proteins. An antibody generated against the Mst98Ca protein recognizes both Mst98C proteins in D. melanogaster. In a male-sterile mutation in which spermiogenesis is blocked before individualization of sperm, both of these proteins are no longer synthesized. This finding provides proof of late translation for the Mst98C proteins and thereby independent proof of translational control of expression. Northern (RNA) and Western immunoblot analyses indicate the presence of homologous gene families in many other Drosophila species. The Mst98C proteins share sequence homology with proteins of the outer dense fibers in mammalian spermatozoa and can be localized to the sperm tail by immunofluorescence with an anti-Mst98Ca antibody.

scholarly journals Genome-wide search and structural and functional analyses for late embryogenesis-abundant (LEA) gene family in poplar

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zihan Cheng ◽  
Xuemei Zhang ◽  
Wenjing Yao ◽  
Kai Zhao ◽  
Lin Liu ◽  
...  
Keyword(s):  
Gene Family ◽  
Higher Plants ◽  
Abiotic Stress Tolerance ◽  
Gene Families ◽  
Regulatory Elements ◽  
Late Embryogenesis Abundant ◽  
Genome Wide ◽  
Lea Gene ◽  
Late Embryogenesis ◽  
Genome Wide Search

Abstract Background The Late Embryogenesis-Abundant (LEA) gene families, which play significant roles in regulation of tolerance to abiotic stresses, widely exist in higher plants. Poplar is a tree species that has important ecological and economic values. But systematic studies on the gene family have not been reported yet in poplar. Results On the basis of genome-wide search, we identified 88 LEA genes from Populus trichocarpa and renamed them as PtrLEA. The PtrLEA genes have fewer introns, and their promoters contain more cis-regulatory elements related to abiotic stress tolerance. Our results from comparative genomics indicated that the PtrLEA genes are conserved and homologous to related genes in other species, such as Eucalyptus robusta, Solanum lycopersicum and Arabidopsis. Using RNA-Seq data collected from poplar under two conditions (with and without salt treatment), we detected 24, 22 and 19 differentially expressed genes (DEGs) in roots, stems and leaves, respectively. Then we performed spatiotemporal expression analysis of the four up-regulated DEGs shared by the tissues, constructed gene co-expression-based networks, and investigated gene function annotations. Conclusion Lines of evidence indicated that the PtrLEA genes play significant roles in poplar growth and development, as well as in responses to salt stress.

scholarly journals Scaffolding proteins guide the evolution of algal light harvesting antennas

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Harry W. Rathbone ◽  
Katharine A. Michie ◽  
Michael J. Landsberg ◽  
Beverley R. Green ◽  
Paul M. G. Curmi
Keyword(s):  
Hydrophobic Surface ◽  
Scaffolding Protein ◽  
Secondary Endosymbiosis ◽  
Scaffolding Proteins ◽  
Α Subunit ◽  
Binding Partner ◽  
Photosynthetic Organisms ◽  
New Family ◽  
Red Algal ◽  
Multiple Copies

AbstractPhotosynthetic organisms have developed diverse antennas composed of chromophorylated proteins to increase photon capture. Cryptophyte algae acquired their photosynthetic organelles (plastids) from a red alga by secondary endosymbiosis. Cryptophytes lost the primary red algal antenna, the red algal phycobilisome, replacing it with a unique antenna composed of αβ protomers, where the β subunit originates from the red algal phycobilisome. The origin of the cryptophyte antenna, particularly the unique α subunit, is unknown. Here we show that the cryptophyte antenna evolved from a complex between a red algal scaffolding protein and phycoerythrin β. Published cryo-EM maps for two red algal phycobilisomes contain clusters of unmodelled density homologous to the cryptophyte-αβ protomer. We modelled these densities, identifying a new family of scaffolding proteins related to red algal phycobilisome linker proteins that possess multiple copies of a cryptophyte-α-like domain. These domains bind to, and stabilise, a conserved hydrophobic surface on phycoerythrin β, which is the same binding site for its primary partner in the red algal phycobilisome, phycoerythrin α. We propose that after endosymbiosis these scaffolding proteins outcompeted the primary binding partner of phycoerythrin β, resulting in the demise of the red algal phycobilisome and emergence of the cryptophyte antenna.

scholarly journals Shoot Regeneration Is Not a Single Cell Event

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 58
Author(s):  
Patharajan Subban ◽  
Yaarit Kutsher ◽  
Dalia Evenor ◽  
Eduard Belausov ◽  
Hanita Zemach ◽  
...  
Keyword(s):  
Gene Family ◽  
Single Cell ◽  
Shoot Regeneration ◽  
Major Gene ◽  
Molecular Genetic ◽  
Plant Biotechnology ◽  
Gene Families ◽  
Regeneration Medium ◽  
Developmental Processes ◽  
Leaf Segments

Shoot regeneration is a key tool of modern plant biotechnology. While many researchers use this process empirically, very little is known about the early molecular genetic factors and signaling events that lead to shoot regeneration. Using tobacco as a model system, we found that the inductive events required for shoot regeneration occur in the first 4–5 days following incubation on regeneration medium. Leaf segments placed on regeneration medium did not produce shoots if removed from the medium before four days indicating this time frame is crucial for the induction of shoot regeneration. Leaf segments placed on regeneration medium for longer than five days maintain the capacity to produce shoots when removed from the regeneration medium. Analysis of gene expression during the early days of incubation on regeneration medium revealed many changes occurring with no single expression pattern evident among major gene families previously implicated in developmental processes. For example, expression of Knotted gene family members increased during the induction period, whereas transcription factors from the Wuschel gene family were unaltered during shoot induction. Expression levels of genes involved in cell cycle regulation increased steadily on regeneration medium while expression of NAC genes varied. No obvious possible candidate genes or developmental processes could be identified as a target for the early events (first few days) in the induction of shoot regeneration. On the other hand, observations during the early stages of regeneration pointed out that regeneration does not occur from a single cell but a group of cells. We observed that while cell division starts just as leaf segments are placed on regeneration medium, only a group of cells could become shoot primordia. Still, these primordia are not identifiable during the first days.

scholarly journals Gene family innovation, conservation and loss on the animal stem lineage

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Daniel J Richter ◽  
Parinaz Fozouni ◽  
Michael B Eisen ◽  
Nicole King
Keyword(s):  
Gene Family ◽  
Gene Families ◽  
Gene Content ◽  
Gene Repertoire ◽  
Toll Like Receptor ◽  
Stem Lineage ◽  
Gains And Losses ◽  
Core Features

Choanoflagellates, the closest living relatives of animals, can provide unique insights into the changes in gene content that preceded the origin of animals. However, only two choanoflagellate genomes are currently available, providing poor coverage of their diversity. We sequenced transcriptomes of 19 additional choanoflagellate species to produce a comprehensive reconstruction of the gains and losses that shaped the ancestral animal gene repertoire. We identified ~1944 gene families that originated on the animal stem lineage, of which only 39 are conserved across all animals in our study. In addition, ~372 gene families previously thought to be animal-specific, including Notch, Delta, and homologs of the animal Toll-like receptor genes, instead evolved prior to the animal-choanoflagellate divergence. Our findings contribute to an increasingly detailed portrait of the gene families that defined the biology of the Urmetazoan and that may underpin core features of extant animals.

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