scholarly journals Cloning and Functional Assessments of Floral-Expressed SWEET Transporter Genes from Jasminum sambac

2019 ◽  
Vol 20 (16) ◽  
pp. 4001 ◽  
Author(s):  
Panpan Wang ◽  
Peining Wei ◽  
Fangfei Niu ◽  
Xiaofeng Liu ◽  
Hongliang Zhang ◽  
...  
Keyword(s):  
Sugar Transport ◽  
Transcript Level ◽  
Cell Uptake ◽  
Functional Assay ◽  
Flower Opening ◽  
Sugar Transporters ◽  
Rapid Amplification ◽  
Fragrance Release ◽  
Jasminum Sambac ◽  
Reproductive Processes

Sugar transporters of the SWEET family mediate cross membrane movement of mono- and disaccharides and play vital roles in diverse physiological and pathophysiological processes, including sink–source relationship, pathogen responses, reproductive growth, and development. However, it remains to be determined how these transporters function in non-module plants of agricultural significance, given the evolutionarily diverse traits. In this study, we combined transcriptome analysis, rapid amplification of cDNA ends-cloning (RACE-cloning), expression profiling, and heterologous functional assay to identify SWEET genes that may have potential roles during flower opening and sexual reproduction in Jasminum sambac . During the anthesis, the floral organs of J. sambac express seven SWEET homologous genes from all four clades of the family. JsSWEET9 and 2 are significantly upregulated when flowers are fully opened, up to 6- and 3-fold compared to unopened buds, respectively. The other transporters, JsSWEET1, 5, 10, and 17 are also accumulated slightly at stage associated with fragrance release, whereas only the vacuole transporter JsSWEET16 showed small decrease in transcript level after anthesis. The JsSWEET5, a clade II member, is capable to complement yeast cell uptake on most tested sugar substrates with a preference for hexoses, while the clade I transporter JsSWEET1 mediates merely galactose import when expressed in yeast. Our results provide first evidence for further investigation on sugar transport and allocation during flowering and reproductive processes in J. sambac.

scholarly journals Role of the SUT1 and SUT2 sugar transporters during stolbur phytoplasma infection in tomato

2020 ◽  
Author(s):  
Federica De Marco ◽  
Brigitte Batailler ◽  
Michael R. Thorpe ◽  
Frédérique Razan ◽  
Rozenn Le Hir ◽  
...  
Keyword(s):  
Redox Homeostasis ◽  
Sugar Transport ◽  
Transcriptional Analysis ◽  
Starch Accumulation ◽  
Metabolic Switch ◽  
Sieve Elements ◽  
Sugar Transporters ◽  
Abnormal Growth ◽  
Sucrose Transporters ◽  
Phytoplasma Infection

SummaryPhytoplasmas inhabit phloem sieve elements and cause abnormal growth and altered sugar partitioning. But how they interact with phloem functions is not clearly known. The phloem responses were investigated in tomato infected by ‘Candidatus Phytoplasma solani’, at the beginning of the symptomatic stage of infection, both in symptomatic and asymptomatic leaves, the first symptoms appearing in the sink top leaf at the stem apex. Antisense lines impaired in the phloem sucrose transporters SUT1 and SUT2 were included. The infection in source leaves was not associated with symptoms. In the symptomatic, sink leaf, yellowing and leaf curling was associated with higher starch accumulation and expression of defense genes. The transcriptional analysis of symptomatic leaf midribs indicated that transcript levels for genes acting in the glycolysis and peroxisome metabolism in infected plants differed from these in non-infected plants. Phytoplasma multiplied actively in at least three additional lower leaves although they were symptomless, with no sign of activation of defense markers, although the rate of exudation of sucrose from these symptomless, source leaves was lower for infected plants. A few metabolites in phloem-enriched exudate were affected by the infection, such as glycolate and aspartate, and some of them were also affected in the control SUT1- and SUT2- antisense lines, in which sucrose retrieval or release in the sieve elements are impaired. A metabolic switch could explain the delivery of more glycolate into the sieve elements of infected plants. The findings suggest a link between sugar transport and redox homeostasis.One sentence summaryAn impairment of sucrose retrieval and release in the sieve elements occurs during phytoplasma infection, associated with changes in sugar and peroxisome metabolism

When SWEETs Turn Tweens: Updates and Perspectives

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Xueyi Xue ◽  
Jiang Wang ◽  
Diwakar Shukla ◽  
Lily S. Cheung ◽  
Li-Qing Chen
Keyword(s):  
Crop Yields ◽  
Sugar Transport ◽  
Basic Research ◽  
Biochemical Properties ◽  
Annual Review ◽  
Publication Date ◽  
Sugar Transporters ◽  
Evolutionary Origins ◽  
Plant Level ◽  
Dynamics Simulations

Sugar translocation between cells and between subcellular compartments in plants requires either plasmodesmata or a diverse array of sugar transporters. Interactions between plants and associated microorganisms also depend on sugar transporters. The sugars will eventually be exported transporter (SWEET) family is made up of conserved and essential transporters involved in many critical biological processes. The functional significance and small size of these proteins have motivated crystallographers to successfully capture several structures of SWEETs and their bacterial homologs in different conformations. These studies together with molecular dynamics simulations have provided unprecedented insights into sugar transport mechanisms in general and into substrate recognition of glucose and sucrose in particular. This review summarizes our current understanding of the SWEET family, from the atomic to the whole-plant level. We cover methods used for their characterization, theories about their evolutionary origins, biochemical properties, physiological functions, and regulation. We also include perspectives on the future work needed to translate basic research into higher crop yields. Expected final online publication date for the Annual Review of Plant Biology, Volume 73 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Treat and trick: common regulation and manipulation of sugar transporters during sink establishment by the plant and the pathogen

2020 ◽  
Vol 71 (14) ◽  
pp. 3930-3940
Author(s):  
Benjamin Pommerrenig ◽  
Christina Müdsam ◽  
Dominik Kischka ◽  
H Ekkehard Neuhaus
Keyword(s):  
Intracellular Transport ◽  
Sugar Transport ◽  
Transport Proteins ◽  
Dependent Manner ◽  
Transport Activity ◽  
Sugar Transporters ◽  
Dependent Processes ◽  
Sink Establishment ◽  
Source And Sink

Abstract Sugar transport proteins are crucial for the coordinated allocation of sugars. In this Expert View we summarize recent key findings of the roles and regulation of sugar transporters in inter- and intracellular transport by focusing on applied approaches, demonstrating how sucrose transporter activity may alter source and sink dynamics and their identities. The plant itself alters its sugar transport activity in a developmentally dependent manner to either establish or load endogenous sinks, for example, during tuber formation and filling. Pathogens represent aberrant sinks that trigger the plant to induce the same processes, resulting in loss of carbon assimilates. We explore common mechanisms of intrinsic, developmentally dependent processes and aberrant, pathogen-induced manipulation of sugar transport. Transporter activity may also be targeted by breeding or genetic modification approaches in crop plants to alter source and sink metabolism upon the overexpression or heterologous expression of these proteins. In addition, we highlight recent progress in the use of sugar analogs to study these processes in vivo.

Comparison of different dietary sugars as inducers of intestinal sugar transporters

1987 ◽  
Vol 252 (4) ◽  
pp. G574-G584 ◽  
Author(s):  
D. H. Solberg ◽  
J. M. Diamond
Keyword(s):  
Small Intestine ◽  
Unit Length ◽  
Sugar Transport ◽  
Dietary Carbohydrate ◽  
Feeding Rates ◽  
Sugar Transporters ◽  
Mouse Small Intestine ◽  
Dietary Fructose ◽  
Carbohydrate Levels ◽  
Dietary Sugars

Intestinal sugar transport increases with dietary carbohydrate levels, but the specific regulatory signals involved have been little studied. Hence we compared rations containing one of five sugars [D-glucose, D-galactose, 3-O-methyl-D-glucose (3-O-MG), D-fructose, and maltose] in their effects on brush-border uptake of five transported solutes (D-glucose, D-galactose, 3-O-MG, D-fructose, and L-proline) by everted sleeves of mouse small intestine. As confirmed by transepithelial potential difference (PD) measurements, there is a distinct fructose transporter that does not evoke a PD, along with one or more aldohexose transporters that do evoke a PD. Galactose and 3-O-MG rations cause a twofold increase in feeding rates, mucosal hyperplasia, and hence nonspecific increases in uptake per unit length of intestine for all transported solutes. Dietary fructose is by far the best specific inducer of the fructose transporter. The five dietary sugars are of fairly similar potency as specific inducers of aldohexose transport, but dietary galactose and fructose may be slightly more potent than glucose. Regulatory signals need not be transported substrates, or vice versa, and need not be metabolizable. Variation in uptake ratios of pairs of aldohexoses with ration and intestinal position suggest multiple aldohexose transporters of overlapping specificity, with different relative activities at different positions and with different susceptibilities to induction by different dietary sugars.

Dietary regulation of intestinal brush-border sugar and amino acid transport in carnivores

1991 ◽  
Vol 261 (4) ◽  
pp. R793-R801 ◽  
Author(s):  
R. K. Buddington ◽  
J. W. Chen ◽  
J. M. Diamond
Keyword(s):  
Brush Border ◽  
Sugar Transport ◽  
Nutrient Transporters ◽  
Sugar Transporters ◽  
Dietary Regulation ◽  
Leopard Frogs ◽  
Intestinal Brush Border ◽  
Carbohydrate Levels

The ability of omnivores and herbivores to regulate reversibly their intestinal brush-border nutrient transporters is functionally related to the unpredictably variable composition of their natural diets. To determine whether carnivores are able similarly to regulate the activities of their intestinal nutrient transporters, we fed to three species of vertebrates that are carnivorous as adults (cats, mink, and leopard frogs) diets with either at least 50% digestible carbohydrate or with negligible carbohydrate levels. Rates of transport for the sugars glucose and fructose and the amino acids (AAs) aspartate, leucine, lysine, and proline were measured throughout the intestine (only proline and glucose in the frogs) by an in vitro everted-sleeve method. Although all three species consume much carbohydrate during early development, only the mink was able to regulate sugar transporter activity in response to changes in levels of dietary carbohydrate. In contrast, the sugar transporters of the cat were unresponsive to varying carbohydrate levels, and long-term feeding of a high-carbohydrate diet caused down-regulation of sugar transport in frogs. Of the three species, only the mink is a member of a family that includes omnivorous species, whereas all members of the families to which the cat and frog belong are carnivorous as adults. All three species were able to regulate rates of AA transport, though the patterns and magnitude of the responses differed between species as well as between AAs, suggesting independent regulation of some AA transporters.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The Structure of the Membrane Protein of SARS-CoV-2 Resembles the Sugar Transporter semiSWEET

2020 ◽  
Author(s):  
Sunil Thomas
Keyword(s):  
In Silico ◽  
Transmembrane Domain ◽  
Sugar Transport ◽  
Protein S ◽  
M Protein ◽  
Sugar Transporter ◽  
Structural Protein ◽  
Sugar Transporters ◽  
And Function ◽  
In Silico Analyses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the disease COVID-19 that has decimated the health and economy of our planet. The virus causes the disease not only in people but also in companion and wild animals. People with diabetes are at risk of the disease. As yet we do not know why the virus is highly successful in causing the pandemic within 3 months of its first report. The structural proteins of SARS include, membrane glycoprotein (M), envelope protein (E), nucleocapsid protein (N) and the spike protein (S). The structure and function of the most abundant structural protein of SARS-CoV-2, the membrane (M) glycoprotein is not fully understood. Using in silico analyses we determined the structure and potential function of the M protein. In silico analyses showed that the M protein of SARS-CoV-2 has a triple helix bundle, form a single 3-transmembrane domain (TM), and are homologous to the prokaryotic sugar transport protein semiSWEET. SemiSWEETs are related to the PQ-loop family that function as cargo receptors in vesicle transport, mediates movement of basic amino acids across lysosomal membranes, and is also involved in phospholipase flippase function. The advantage and role of sugar transporter-like structure in viruses is unknown. Endocytosis is critical for the internalization and maturation of RNA viruses, including SARS-CoV-2. Sucrose is involved in endosome and lysosome maturation and may also induce autophagy, pathways that help in the entry of the virus. It could be hypothesized that the semiSWEET sugar transporters could be used in multiple pathways that may aid in the rapid proliferation and replication of the virus. Biological experiments would validate the presence and function of the semiSWEET sugar transporter.

scholarly journals The Structure of the Membrane Protein of SARS-CoV-2 Resembles the Sugar Transporter semiSWEET

2020 ◽  
Author(s):  
Sunil Thomas
Keyword(s):  
In Silico ◽  
Transmembrane Domain ◽  
Sugar Transport ◽  
Protein S ◽  
M Protein ◽  
Sugar Transporter ◽  
Structural Protein ◽  
Sugar Transporters ◽  
And Function ◽  
In Silico Analyses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the disease COVID-19 that has decimated the health and economy of our planet. The virus causes the disease not only in people but also in companion and wild animals. People with diabetes are at risk of the disease. As yet we do not know why the virus is highly successful in causing the pandemic within 3 months of its first report. The structural proteins of SARS include, membrane glycoprotein (M), envelope protein (E), nucleocapsid protein (N) and the spike protein (S). The structure and function of the most abundant structural protein of SARS-CoV-2, the membrane (M) glycoprotein is not fully understood. Using in silico analyses we determined the structure and potential function of the M protein. The M protein of SARS-CoV-2 is 98.6% similar to the M protein of bat SARS-CoV, maintains 98.2% homology with pangolin SARS-CoV, and has 90% homology with M protein of SARS-CoV; whereas, the similarity was only 38% with the M protein of MERS-CoV. In silico analyses showed that the M protein of SARS-CoV-2 has a triple helix bundle, form a single 3-transmembrane domain (TM), and are homologous to the prokaryotic sugar transport protein semiSWEET. SemiSWEETs are related to the PQ-loop family that function as cargo receptors in vesicle transport, mediates movement of basic amino acids across lysosomal membranes, and is also involved in phospholipase flippase function. The advantage and role of sugar transporter-like structure in viruses is unknown. Endocytosis is critical for the internalization and maturation of RNA viruses, including SARS-CoV-2. Sucrose is involved in endosome and lysosome maturation and may also induce autophagy, pathways that help in the entry of the virus. It could be hypothesized that the semiSWEET sugar transporters could be used in multiple pathways that may aid in the rapid proliferation and replication of the virus. Biological experiments would validate the presence and function of the semiSWEET sugar transporter.

'Active' sugar transport in eukaryotes.

1994 ◽  
Vol 196 (1) ◽  
pp. 197-212 ◽  
Author(s):  
E M Wright ◽  
D D Loo ◽  
M Panayotova-Heiermann ◽  
M P Lostao ◽  
B H Hirayama ◽  
...  
Keyword(s):  
Gene Family ◽  
Conformational Changes ◽  
Sugar Transport ◽  
Large Family ◽  
Site Directed Mutagenesis ◽  
Xenopus Laevis Oocytes ◽  
Alpha Helices ◽  
Sugar Transporters ◽  
Ultrastructural Studies ◽  
Kinetics Of

Sugar transporters in prokaryotes and eukaryotes belong to a large family of membrane proteins containing 12 transmembrane alpha-helices. They are divided into two classes: one facilitative (uniporters) and the other concentrative (cotransporters or symporters). The concentrative transporters are energised by either H+ or Na+ gradients, which are generated and maintained by ion pumps. The facilitative and H(+)-driven sugar transporters belong to a gene family with a distinctive secondary structure profile. The Na(+)-driven transporters belong to a separate, small gene family with no homology at either the primary or secondary structural levels. It is likely that the Na(+)- and H(+)-driven sugar cotransporters share common transport mechanisms. To explore these mechanisms, we have expressed cloned eukaryote Na+/sugar cotransporters (SGLT) in Xenopus laevis oocytes and measured the kinetics of sugar transport using two-electrode voltage-clamp techniques. For SGLT1, we have developed a six-state ordered model that accounts for the experimental data. To test the model we have carried out the following experiments. (i) We measured pre-steady-state kinetics of SGLT1 using voltage-jump techniques. In the absence of sugar, SGLT1 exhibits transient carrier currents that reflect voltage-dependent conformational changes of the protein. Time constants for the carrier currents give estimates of rate constants for the conformational changes, and the charge movements, integrals of the transient currents, give estimates of the number and valence of SGLT1 proteins in the plasma membrane. Ultrastructural studies have confirmed these estimates of SGLT1 density. (ii) We have perturbed the kinetics of the cotransporter by site-directed mutagenesis of selected residues.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals SLC35A5 Protein—A Golgi Complex Member with Putative Nucleotide Sugar Transport Activity

2019 ◽  
Vol 20 (2) ◽  
pp. 276 ◽  
Author(s):  
Paulina Sosicka ◽  
Bożena Bazan ◽  
Dorota Maszczak-Seneczko ◽  
Yauhen Shauchuk ◽  
Teresa Olczak ◽  
...  
Keyword(s):  
Protein A ◽  
Sugar Transport ◽  
Uridine Diphosphate ◽  
Transport Activity ◽  
Nucleotide Sugar ◽  
Knock Out ◽  
Sugar Transporters ◽  
C Terminus ◽  
Glycolipid Synthesis ◽  
Galactose Transport

Solute carrier family 35 member A5 (SLC35A5) is a member of the SLC35A protein subfamily comprising nucleotide sugar transporters. However, the function of SLC35A5 is yet to be experimentally determined. In this study, we inactivated the SLC35A5 gene in the HepG2 cell line to study a potential role of this protein in glycosylation. Introduced modification affected neither N- nor O-glycans. There was also no influence of the gene knock-out on glycolipid synthesis. However, inactivation of the SLC35A5 gene caused a slight increase in the level of chondroitin sulfate proteoglycans. Moreover, inactivation of the SLC35A5 gene resulted in the decrease of the uridine diphosphate (UDP)-glucuronic acid, UDP-N-acetylglucosamine, and UDP-N-acetylgalactosamine Golgi uptake, with no influence on the UDP-galactose transport activity. Further studies demonstrated that SLC35A5 localized exclusively to the Golgi apparatus. Careful insight into the protein sequence revealed that the C-terminus of this protein is extremely acidic and contains distinctive motifs, namely DXEE, DXD, and DXXD. Our studies show that the C-terminus is directed toward the cytosol. We also demonstrated that SLC35A5 formed homomers, as well as heteromers with other members of the SLC35A protein subfamily. In conclusion, the SLC35A5 protein might be a Golgi-resident multiprotein complex member engaged in nucleotide sugar transport.

Cloning and characterization of MdGST1 from red apple leaves

2018 ◽  
Vol 98 (5) ◽  
pp. 1150-1158
Author(s):  
Xiaolei Han ◽  
Caixia Zhang ◽  
Yi Tian ◽  
Hera Gul ◽  
Peihua Cong ◽  
...  
Keyword(s):  
Anthocyanin Biosynthesis ◽  
Transcript Level ◽  
Glutathione S Transferase ◽  
Gene Encoding ◽  
Protein Coding ◽  
Apple Variety ◽  
Coding Regions ◽  
Qrt Pcr ◽  
Rapid Amplification

Glutathione S-transferase (GST) is involved in the downstream steps of the anthocyanin biosynthesis pathway in plants. However, the gene(s) encoding this enzyme have not been isolated from apple (Malus × domestica Borkh.) yet. We isolated a gene encoding GST from leaves of the red-fleshed apple variety ‘Royalty’ by full cDNA library sequencing and the 3′ rapid-amplification of cDNA ends method, and designated it MdGST1. In total, seven different MdGST1 transcripts were found. These had three different untranslated but identical protein-coding regions. Phylogenetic analysis showed that MdGST1 is a TT19-type GST, which is involved in anthocyanin transport. qRT-PCR analyses showed that the transcript level of MdGST1 was much higher in red leaves than in bagged or green leaves. When MdGST1 was introduced into a non-pigmented mutant of Arabidopsis, the transformants showed a visible purple phenotype in leaves and stems. Our results suggest that MdGST1 plays a role in anthocyanin biosynthesis. This information will help to improve the understanding of the mechanism of apple coloration.

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