scholarly journals Ceramide Synthase 6: Comparative Analysis, Phylogeny and Evolution

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 111 ◽  
Author(s):  
Roger Holmes ◽  
Keri Barron ◽  
Natalia Krupenko

Ceramide synthase 6 (CerS6, also known as LASS6) is one of the six members of ceramide synthase gene family in humans. Comparisons of CerS6 amino acid sequences and structures as well as of CerS6 gene structures/locations were conducted using data from several vertebrate genome projects. A specific role for the CerS6 gene and protein has been identified as the endoplasmic reticulum C14- and C16-ceramide synthase. Mammalian CerS6 proteins share 90–100% similarity among different species, but are only 22–63% similar to other CerS family members, suggesting that CerS6 is a distinct gene family. Sequence alignments, predicted transmembrane, lumenal and cytoplasmic segments and N-glycosylation sites were also investigated, resulting in identification of the key conserved residues, including the active site as well as C-terminus acidic and serine residues. Mammalian CerS6 genes contain ten exons, are primarily located on the positive strands and transcribed as two major isoforms. The human CERS6 gene promoter harbors a large CpG island (94 CpGs) and multiple transcription factor binding sites (TFBS), which support precise transcriptional regulation and signaling functions. Additional regulation is conferred by 15 microRNA (miRNA) target sites identified in the CERS6 3′-UTR region. Phylogenetic analysis of the vertebrate CerS1–6 gene families relationships supports a major role for the CerS6 enzyme that is strongly conserved throughout vertebrate evolution.

1998 ◽  
Vol 330 (1) ◽  
pp. 169-173 ◽  
Author(s):  
M. Linda FIELD ◽  
L. Alan DEVONSHIRE

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.


2018 ◽  
Vol 10 (8) ◽  
pp. 56
Author(s):  
Goitseone Malambane ◽  
Hisashi Tsujimoto ◽  
Kinya Akashi

Ascorbate peroxidase (APX) plays an important role in detoxifying reactive oxygen species under environmental stress. Although previous work in drought-tolerant wild watermelon has shown an increase in chloroplast APX enzyme activity under drought, molecular entities of APX have remained uncharacterized. In this study, structure and transcriptional regulation of the APX gene family in watermelon were characterized. Five APX genes, designated as CLAPX1 to CLAPX5, were identified from watermelon genome. The mRNA alternative splicing was suggested for CLAPX5, which generated two distinct deduced amino acid sequences at their C-terminus, in resemblance to a reported alternative splicing of chloroplast APXs in pumpkin. This observation suggests that two isoenzymes for stromal and thylakoid-bound APXs may be generated from the CLAPX5 gene. Phylogenetic analysis classified CLAPX isoenzymes into three clades, i.e., chloroplast, microbody, and cytosolic. Physiological analyses of wild watermelon under drought showed a decline in stomatal conductance and CO2 assimilation rate, and a significant increase in the enzyme activities of both chloroplast and cytosolic APXs. Profiles of mRNA abundance during drought were markedly different among CLAPX genes, suggesting distinct transcriptional regulation for the APX isoenzymes. Up-regulation of CLAPX5-I and CLAPX5-II was observed at the early phase of drought stress, which was temporally correlated with the observed increase in chloroplast APX enzyme activity, suggesting that transcriptional up-regulation of the CLAPX5 gene may contribute to the fortification of chloroplast APX activity under drought. Our study has provided an insight into the functional significance of the CLAPX gene family in the drought tolerance mechanism in this plant.


Cholesterol ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Roger S. Holmes ◽  
Laura A. Cox

Bile-salt activated carboxylic ester lipase (CEL) is a major triglyceride, cholesterol ester and vitamin ester hydrolytic enzyme contained within pancreatic and lactating mammary gland secretions. Bioinformatic methods were used to predict the amino acid sequences, secondary and tertiary structures and gene locations for CEL genes, and encoded proteins using data from several vertebrate genome projects. A proline-rich and O-glycosylated 11-amino acid C-terminal repeat sequence (VNTR) previously reported for human and other higher primate CEL proteins was also observed for other eutherian mammalian CEL sequences examined. In contrast, opossum CEL contained a single C-terminal copy of this sequence whereas CEL proteins from platypus, chicken, lizard, frog and several fish species lacked the VNTR sequence. Vertebrate CEL genes contained 11 coding exons. Evidence is presented for tandem duplicated CEL genes for the zebrafish genome. Vertebrate CEL protein subunits shared 53–97% sequence identities; demonstrated sequence alignments and identities for key CEL amino acid residues; and conservation of predicted secondary and tertiary structures with those previously reported for human CEL. Phylogenetic analyses demonstrated the relationships and potential evolutionary origins of the vertebrate CEL family of genes which were related to a nematode carboxylesterase (CES) gene and five mammalian CES gene families.


2020 ◽  
Author(s):  
Min Song ◽  
Di Wu ◽  
Anqi Liu ◽  
Xiaoyu Qu ◽  
Jiayi Liang

Abstract Background Xyloglucan endotransglucosylase/hydrolase genes (XTHs) are a multigene family and play key roles in regulating cell wall extensibility in plant growth and development. XTH genes of Brassica have not been reported. Results In this study, 53 and 38 XTH genes were identified in Brassica rapa and Brassica olerecea, respectively. All XTHs of B. rapa, B. oleracea and Arabidopsis thaliana can be classified into three groups including Group I/II, III and Ancestral Group based on phylogenetic relationships. Gene structures and motif patterns were similar in the same group. All XTHs in this study contained two characteristic conserved domains (Glyco_hydro and XET_C). XTHs mainly located in the cell wall and some also located in cytoplasm. Expansion mechanism analyses uncovered that whole-genome triplication (WGT) events and tandem duplication (TD) may be the major mechanism accounting for the expansion of XTH gene family. Interestingly, TD genes were all belong to Group I/II, which suggested TD was the main reason for the largest number of genes in the groups. B. oleracea had a higher loss rate of XTH genes, conserved domain XET_C and conserved motif EXDXE compared with B. rapa, consistent with the asymmetrical evolution between the two Brassica genomes. A majority of XTH genes exhibited different tissue-specific expression patterns based on RNA-seq data analyses. Moreover, the differential expressions of duplicated XTH genes in the two species were found and indicated their functional differentiation occurred after B. rapa and B. olerecea diverged from a common ancestor. Conclusions We first systematic analyzed XTH gene families in B. rapa and B. oleracea. The results of this paper can be used for reference to further study the function of XTH gene and the evolution pattern of multi gene family.


2019 ◽  
Author(s):  
Eduardo Pérez-Palma ◽  
Patrick May ◽  
Sumaiya Iqbal ◽  
Lisa-Marie Niestroj ◽  
Juanjiangmeng Du ◽  
...  

AbstractMissense variant interpretation is challenging. Essential regions for protein function are conserved among gene family members, and genetic variants within these regions are potentially more likely to confer risk to disease. Here, we generated 2,871 gene family protein sequence alignments involving 9,990 genes and performed missense variant burden analyses to identify novel essential protein regions. We mapped 2,219,811 variants from the general population into these alignments and compared their distribution with 65,034 missense variants from patients. With this gene family approach, we identified 398 regions enriched for patient variants spanning 33,887 amino acids in 1,058 genes. As a comparison, testing the same genes individually we identified less patient variant enriched regions involving only 2,167 amino acids and 180 genes. Next, we selected de novo variants from 6,753 patients with neurodevelopmental disorders and 1,911 unaffected siblings, and observed a 5.56-fold enrichment of patient variants in our identified regions (95% C.I. =2.76-Inf, p-value = 6.66×10−8). Using an independent ClinVar variant set, we found missense variants inside the identified regions are 111-fold more likely to be classified as pathogenic in comparison to benign classification (OR = 111.48, 95% C.I = 68.09-195.58, p-value < 2.2e−16). All patient variant enriched regions identified (PERs) are available online through a user-friendly platform for interactive data mining, visualization and download at http://per.broadinstitute.org. In summary, our gene family burden analysis approach identified novel patient variant enriched regions in protein sequences. This annotation can empower variant interpretation.


Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 1021-1031 ◽  
Author(s):  
Jianping Hu ◽  
Beth Anderson ◽  
Susan R Wessler

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.


2020 ◽  
Vol 22 (1) ◽  
pp. 253
Author(s):  
Venura Herath ◽  
Jeanmarie Verchot

The basic region-leucine zipper (bZIP) transcription factors (TFs) form homodimers and heterodimers via the coil–coil region. The bZIP dimerization network influences gene expression across plant development and in response to a range of environmental stresses. The recent release of the most comprehensive potato reference genome was used to identify 80 StbZIP genes and to characterize their gene structure, phylogenetic relationships, and gene expression profiles. The StbZIP genes have undergone 22 segmental and one tandem duplication events. Ka/Ks analysis suggested that most duplications experienced purifying selection. Amino acid sequence alignments and phylogenetic comparisons made with the Arabidopsis bZIP family were used to assign the StbZIP genes to functional groups based on the Arabidopsis orthologs. The patterns of introns and exons were conserved within the assigned functional groups which are supportive of the phylogeny and evidence of a common progenitor. Inspection of the leucine repeat heptads within the bZIP domains identified a pattern of attractive pairs favoring homodimerization, and repulsive pairs favoring heterodimerization. These patterns of attractive and repulsive heptads were similar within each functional group for Arabidopsis and S. tuberosum orthologs. High-throughput RNA-seq data indicated the most highly expressed and repressed genes that might play significant roles in tissue growth and development, abiotic stress response, and response to pathogens including Potato virus X. These data provide useful information for further functional analysis of the StbZIP gene family and their potential applications in crop improvement.


1993 ◽  
Vol 13 (3) ◽  
pp. 1708-1718 ◽  
Author(s):  
M Schäfer ◽  
D Börsch ◽  
A Hülster ◽  
U Schäfer

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.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zihan Cheng ◽  
Xuemei Zhang ◽  
Wenjing Yao ◽  
Kai Zhao ◽  
Lin Liu ◽  
...  

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.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 58
Author(s):  
Patharajan Subban ◽  
Yaarit Kutsher ◽  
Dalia Evenor ◽  
Eduard Belausov ◽  
Hanita Zemach ◽  
...  

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.


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