SAS1 and SAS2, GTP-binding protein genes in Dictyostelium discoideum with sequence similarities to essential genes in Saccharomyces cerevisiae

1990 ◽  
Vol 10 (5) ◽  
pp. 2367-2378
Author(s):  
S A Saxe ◽  
A R Kimmel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dictyostelium Discoideum ◽  
Intracellular Signaling ◽  
Repetitive Element ◽  
Expression Patterns ◽  
Mrna Levels ◽  
Developmentally Regulated ◽  
Membrane Function ◽  
Gtp Binding ◽  
Regulated Gene Expression

We have identified two novel, very closely related genes, SAS1 and SAS2, from Dictyostelium discoideum. These encode small, approximately 20-kilodaton proteins with amino acid sequences thought to be involved in interaction with guanine nucleotides. The protein sizes, spacings of GTP-binding domains, and carboxyl-terminal sequences suggest their relationship to the ubiquitous ras-type proteins. Their sequences, however, are sufficiently different to indicate that they are not true ras proteins. More extensive sequence identity (approximately 55%) is shared with the YPT1 and SEC4 proteins from Saccharomyces cerevisiae. These yeast proteins are essential for growth and are believed to be involved in intracellular signaling associated with membrane function. SAS1 and SAS2 exhibit distinct patterns of genomic organization and developmentally regulated gene expression. SAS1 contains introns and is associated with a developmentally regulated repetitive element. SAS2 is colinear with its mRNA and does not appear to be closely linked with this repetitive element. Both genes are expressed during growth and throughout development. SAS1 is maximally expressed during cytodifferentiation, when two sizes of SAS1 mRNA are detectable. SAS2 mRNA levels are maximal during culmination. On the basis of the expression patterns of the SAS genes and their relationship to the YPT1 and SEC4 genes, we discuss possible functions of the SAS proteins.

scholarly journals SAS1 and SAS2, GTP-binding protein genes in Dictyostelium discoideum with sequence similarities to essential genes in Saccharomyces cerevisiae.

1990 ◽  
Vol 10 (5) ◽  
pp. 2367-2378 ◽  
Author(s):  
S A Saxe ◽  
A R Kimmel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dictyostelium Discoideum ◽  
Intracellular Signaling ◽  
Repetitive Element ◽  
Expression Patterns ◽  
Mrna Levels ◽  
Developmentally Regulated ◽  
Membrane Function ◽  
Gtp Binding ◽  
Regulated Gene Expression

We have identified two novel, very closely related genes, SAS1 and SAS2, from Dictyostelium discoideum. These encode small, approximately 20-kilodaton proteins with amino acid sequences thought to be involved in interaction with guanine nucleotides. The protein sizes, spacings of GTP-binding domains, and carboxyl-terminal sequences suggest their relationship to the ubiquitous ras-type proteins. Their sequences, however, are sufficiently different to indicate that they are not true ras proteins. More extensive sequence identity (approximately 55%) is shared with the YPT1 and SEC4 proteins from Saccharomyces cerevisiae. These yeast proteins are essential for growth and are believed to be involved in intracellular signaling associated with membrane function. SAS1 and SAS2 exhibit distinct patterns of genomic organization and developmentally regulated gene expression. SAS1 contains introns and is associated with a developmentally regulated repetitive element. SAS2 is colinear with its mRNA and does not appear to be closely linked with this repetitive element. Both genes are expressed during growth and throughout development. SAS1 is maximally expressed during cytodifferentiation, when two sizes of SAS1 mRNA are detectable. SAS2 mRNA levels are maximal during culmination. On the basis of the expression patterns of the SAS genes and their relationship to the YPT1 and SEC4 genes, we discuss possible functions of the SAS proteins.

scholarly journals The Let-7 Chronoregulatory Cascade Components May Act Independently to Regulate Fetal Hemoglobin in Human Adult Erythroblasts

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 944-944
Author(s):  
Jaira F. de Vasconcellos ◽  
Colleen Byrnes ◽  
Y. Terry Lee ◽  
May Li ◽  
Antoinette Rabel ◽  
...  
Keyword(s):  
Cord Blood ◽  
Globin Gene ◽  
Expression Patterns ◽  
Detection Limits ◽  
Fetal Hemoglobin ◽  
Mrna Levels ◽  
Developmentally Regulated ◽  
Adult Transition ◽  
Background Levels ◽  
Adult Cells

Abstract Multiple components of the highly conserved let-7 cascade are developmentally regulated during the fetal-to adult transition of human ontogeny. Previous studies showed the let-7 miRNAs to be correlated with the developmentally regulated expression of fetal hemoglobin (HbF) in humans. Ex vivo manipulation of the main known let-7 regulator (LIN28) and downstream let-7 targets (IGF2BP1, IGF2BP3 and HMGA2) have shown variant increases in HbF levels (ranging from around 15-68% HbF) among cultured adult human erythroid cells. In addition, IGF2BP1 over-expression (OE) in cord blood erythroblasts raised HbF levels to an average of 90% compared to 55% in control transductions. Remarkably, in the fetal environment, the manipulation of the let-7 cascade has profound effects on HbF levels (cord blood control for the OE vectors: 57.4 ± 8.6%; LIN28A-OE: 90.8 ± 1.7%, p = 0.0003; IGF2BP3-OE: 79.0 ± 3.8%, p=0.001; HMGA2-OE: 73.4 ± 3.1, p=0.014; control for the tough decoy (TuD) vector: 51.6 ± 5.7%; let-7a-TuD: 90.3 ± 2.5%, p=0.001). As such, we hypothesized that the variable HbF effects in the adult cells may be due to independent or parallel effects from each component of the let-7 cascade since LIN28, IGF2BP1, IGF2BP3 and HMGA2 are expressed at very low levels or undetectable in the erythroid compartment after the fetal-to-adult transition. For these studies, lentiviral transduction of human CD34+ cells were investigated in erythropoietin-supplemented serum-free cultures for 21 days and compared to donor-matched control transductions. Based upon its important role in globin gene regulation, mRNA and protein expression patterns of the transcription factor BCL11A were investigated by RT-qPCR and Western blot at day 14 as a mechanism for HbF regulation by the let-7 cascade components. BCL11A mRNA was significantly down-regulated after LIN28A-OE (control: 4.1.E+03 ± 8.2.E+02 copies/ng, LIN28A-OE: 1.7.E+03 ± 1.2.E+03 copies/ng, p=0.04) and let-7a -TuD (control: 1.7E+03 ± 4.5E+02 copies/ng, let-7a-TuD: 4.3E+02 ± 1.8E+02 copies/ng, p=0.003), while no significant differences were observed after IGF2BP1-OE (control: 5.42.E+03 ± 1.77.E+03 copies/ng, IGF2BP1-OE: 4.38.E+03 ± 2.57.E+02 copies/ng, p=0.375), IGF2BP3-OE (control: 5.64.E+02 ± 2.68.E+02 copies/ng, IGF2BP3-OE: 6.70.E+02 ± 3.47.E+02 copies/ng, p=0.694) and HMGA2-OE (control: 4.26E+02 ± 8.18E+01 copies/ng, HMGA2-OE: 2.84E+02 ± 1.48E+02 copies/ng, p=0.104). Interestingly, the protein levels of BCL11A were consistently down-regulated only by LIN28A-OE, let-7a -TuD and IGF2BP1-OE, with minimal changes observed after IGF2BP3-OE and HMGA2-OE. To investigate which elements of the let-7 cascade are required for the fetal hemoglobin effects in adult cells, the expression levels of each component were compared with HbF effects after lentiviral-mediated transduction of LIN28A-OE, let-7a -TuD, IGF2BP1-OE, IGF2BP3-OE, or HMGA2-OE. RT-qPCR analyses were performed at day 14 and HPLC at day 21. HbF levels for the control transductions were less than 5%. Following LIN28A-OE (HbF: LIN28A-OE: 34.8 ± 2.7%, p=0.028), both IGF2BP1 and IGF2BP3 mRNA levels remained below the detection limits, while HMGA2 was slightly down-regulated. After let-7a -TuD (HbF: let-7a-TuD: 31.0 ± 5.0%, p=0.09), LIN28A and HMGA2 remained at background levels while IGF2BP1 and IGF2BP3 were below the detection limits. Following IGF2BP1-OE (HbF: IGF2BP1-OE: 64.6 ± 3.4%, p=0.02), LIN28A, IGF2BP3, and HMGA2 remained undetectable or at background levels. After IGF2BP3-OE (HbF: IGF2BP3-OE: 22.8 ± 4.4%, p=0.021), LIN28A, IGF2BP1 and HMGA2 also remained unchanged at background or undetectable levels. Finally, after HMGA2-OE (HbF: HMGA2-OE: 13.5 ± 1.5%, p=0.01), LIN28A, IGF2BP1 and IGF2BP3 remained below the detection limits. These results were confirmed by Western analysis, with the exception of HMGA2, which was consistently increased at the protein level following LIN28A-OE, let-7a -TuD, IGF2BP1-OE and IGF2BP3-OE. In summary, these results demonstrate that several components the let-7 cascade share a downstream mechanism of BCL11A protein suppression in human erythroblasts. However, the variability of BCL11A and HbF effects as well as the ability of LIN28A-OE, let-7a-TuD and HMGA2-OE to increase HbF in the absence of IGF2BP1 and IGF2BP3 suggest both shared and independent mechanisms for hemoglobin regulation by the let-7 cascade during the human fetal-to-adult switch. Disclosures No relevant conflicts of interest to declare.

scholarly journals GAS2 and GAS4, a Pair of Developmentally Regulated Genes Required for Spore Wall Assembly in Saccharomyces cerevisiae

2007 ◽  
Vol 6 (2) ◽  
pp. 302-316 ◽  
Author(s):  
Enrico Ragni ◽  
Alison Coluccio ◽  
Eleonora Rolli ◽  
José Manuel Rodriguez-Peña ◽  
Gaia Colasante ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ph Value ◽  
Ectopic Expression ◽  
Spore Wall ◽  
Mrna Levels ◽  
Developmentally Regulated ◽  
Cell Wall Assembly ◽  
Severe Reduction ◽  
Spore Ultrastructure ◽  
Wall Assembly

ABSTRACT The GAS multigene family of Saccharomyces cerevisiae is composed of five paralogs (GAS1 to GAS5). GAS1 is the only one of these genes that has been characterized to date. It encodes a glycosylphosphatidylinositol-anchored protein functioning as aβ (1,3)-glucan elongase and required for proper cell wall assembly during vegetative growth. In this study, we characterize the roles of the GAS2 and GAS4 genes. These genes are expressed exclusively during sporulation. Their mRNA levels showed a peak at 7 h from induction of sporulation and then decreased. Gas2 and Gas4 proteins were detected and reached maximum levels between 8 and 10 h from induction of sporulation, a time roughly coincident with spore wall assembly. The double null gas2 gas4 diploid mutant showed a severe reduction in the efficiency of sporulation, an increased permeability of the spores to exogenous substances, and production of inviable spores, whereas the single gas2 and gas4 null diploids were similar to the parental strain. An analysis of spore ultrastructure indicated that the loss of Gas2 and Gas4 proteins affected the proper attachment of the glucan to the chitosan layer, probably as a consequence of the lack of coherence of the glucan layer. The ectopic expression of GAS2 and GAS4 genes in a gas1 null mutant revealed that these proteins are redundant versions of Gas1p specialized to function in a compartment at a pH value close to neutral.

scholarly journals Lithium ions induce prestalk-associated gene expression and inhibit prespore gene expression in Dictyostelium discoideum

1989 ◽  
Vol 93 (1) ◽  
pp. 205-210
Author(s):  
D.J. Peters ◽  
M.M. Van Lookeren Campagne ◽  
P.J. Van Haastert ◽  
W. Spek ◽  
P. Schaap
Keyword(s):  
Gene Expression ◽  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Cysteine Proteinase ◽  
Mrna Levels ◽  
Lithium Ions ◽  
Maximal Inhibition ◽  
Regulated Gene Expression

We investigated the effect of Li+ on two types of cyclic AMP-regulated gene expression and on basal and cyclic AMP-stimulated inositol 1,4,5-triphosphate (Ins(1,4,5)P3) levels. Li+ effectively inhibits cyclic AMP-induced prespore gene expression, half-maximal inhibition occurring at about 2 mM-LiCl. In contrast, Li+ (1–3 mM) promotes the cyclic AMP-induced increase of cysteine proteinase-2 mRNA levels, and induces the expression of this prestalk-associated gene in the absence of cyclic AMP stimuli. At concentrations exceeding 4–5 mM, LiCl inhibits cysteine proteinase-2 gene expression. LiCl reduces basal Ins(1,4,5)P3 levels and decreases the cyclic AMP-induced accumulation of Ins(1,4,5)P3; both effects occur half-maximally at 2–3 mM-LiCl. These results indicate that the induction of the cysteine proteinase-2 gene by Li+ is not due to elevated levels of Ins(1,4,5)P3. It is, however, possible that inhibition of prespore gene expression by Li+ is caused by Li+-induced reduction of basal and/or stimulated Ins(1,4,5)P3 levels.

scholarly journals Analysis of p53-regulated gene expression patterns using oligonucleotide arrays

2000 ◽  
Vol 14 (8) ◽  
pp. 981-993 ◽  
Author(s):  
Renbin Zhao ◽  
Kurt Gish ◽  
Maureen Murphy ◽  
Yuxin Yin ◽  
Daniel Notterman ◽  
...  
Keyword(s):  
P53 Protein ◽  
Expression Patterns ◽  
Mrna Levels ◽  
Cell Type ◽  
Oligonucleotide Arrays ◽  
Γ Radiation ◽  
P53 Response ◽  
A Cell ◽  
Regulated Gene Expression ◽  
Kinetics Of

Oligonucleotide microarrays were employed to quantitate mRNA levels from a large number of genes regulated by the p53 transcription factor. Responses to DNA damage and to zinc-inducible p53 were compared for their transcription patterns in cell culture. A cluster analysis of these data demonstrates that genes induced by γ radiation, UV radiation, and the zinc-induced p53 form distinct sets and subsets with a few genes in common to all these treatments. Cell type- or cell line-specific p53 responses were detected. When p53 proteins were induced with zinc, the kinetics of induction or repression of mRNAs from p53-responsive genes fell into eight distinct classes, five different kinetics of induction, and three different kinetics of repression. In addition, low levels of p53 in a cell induced or repressed only a subset of genes observed at higher p53 levels. The results of this study demonstrate that the nature of the p53 response in diverse mRNA species depends on the levels of p53 protein in a cell, the type of inducing agent or event, and the cell type employed. Of 6000 genes examined for p53 regulatory responses, 107 induced and 54 repressed genes fell into categories of apoptosis and growth arrest, cytoskeletal functions, growth factors and their inhibitors, extracellular matrix, and adhesion genes.

Identification of Differentially Expressed Genes Using cDNA-AFLP During Six Days In Vitro Tuberization of Potato

Zuriat ◽  
2015 ◽  
Vol 14 (1) ◽  
Author(s):  
Nono Carsono ◽  
Christian Bachem
Keyword(s):  
Gene Expression ◽  
Developmental Process ◽  
Expression Patterns ◽  
Induction Medium ◽  
In Vitro Tuberization ◽  
Storage Organ ◽  
Developmentally Regulated ◽  
Study Gene Expression ◽  
Differential Pattern

Tuberization in potato is a complex developmental process resulting in the differentiation of stolon into the storage organ, tuber. During tuberization, change in gene expression has been known to occur. To study gene expression during tuberization over the time, in vitro tuberization system provides a suitable tool, due to its synchronous in tuber formation. An early six days axillary bud growing on tuber induction medium is a crucial development since a large number of genes change in their expression patterns during this period. In order to identify, isolate and sequencing the genes which displaying differential pattern between tuberizing and non-tuberizing potato explants during six days in vitro tuberization, cDNA-AFLP fingerprint, method for the visualization of gene expression using cDNA as template which is amplified to generate an RNA-fingerprinting, was used in this experiment. Seventeen primer combinations were chosen based on their expression profile from cDNA-AFLP fingerprint. Forty five TDFs (transcript derived fragment), which displayed differential expressions, were obtained. Tuberizing explants had much more TDFs, which developmentally regulated, than those from non tuberizing explants. Seven TDFs were isolated, cloned and then sequenced. One TDF did not find similarity in the current databases. The nucleotide sequence of TDF F showed best similarity to invertase ezymes from the databases. The homology of six TDFs with known sequences is discussed in this paper.

Nanocurcumin: A Double-Edged Sword for Microcancers

2020 ◽  
Vol 26 (45) ◽  
pp. 5783-5792
Author(s):  
Kholood Abid Janjua ◽  
Adeeb Shehzad ◽  
Raheem Shahzad ◽  
Salman Ul Islam ◽  
Mazhar Ul Islam
Keyword(s):  
Intracellular Signaling ◽  
Dosage Forms ◽  
The Body ◽  
In Vivo Studies ◽  
Mrna Levels ◽  
Anticancer Activities ◽  
Road Map ◽  
Anticancer Effects

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.

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