Sex determination in loggerhead turtles: differential expression of two hnRNP proteins

Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 305-312
Author(s):  
J.L. Harry ◽  
K.L. Williams ◽  
D.A. Briscoe
Keyword(s):  
Monoclonal Antibody ◽  
Sex Determination ◽  
Transcriptional Control ◽  
Rna Binding ◽  
Incubation Temperature ◽  
Constitutive Expression ◽  
Loggerhead Turtle ◽  
Differentially Expressed ◽  
Heat Shock Gene ◽  
Hnrnp Proteins

Sex determination in the loggerhead turtle, Caretta caretta, is controlled by incubation temperature during a critical period of embryogenesis. As heat-shock gene expression is temperature-dependent and has been shown to be associated with early developmental regulation in several organisms, we studied the constitutive expression of hsp70 and hsp90 in embryonic brain and urinogenital tissues to see if these proteins are differentially expressed during the sex-determining period in embryos incubated at male- (26 degrees C) and female- (32 degrees C) determining temperatures. The level of expression of hsp70 and hsp90, as determined from monoclonal antibody staining, is similar in both sexes during the sex-determining period. However, AC88, a monoclonal antibody that identifies hsp90 in several systems, recognised two additional protein bands (Mr 42 and 46 × 10(3)), which are differentially expressed in the urinogenital tissue of developing male and female embryos during the sex-determining period. While the 42K and 46K proteins appear in the urinogenital tissue of developing female (32 degrees C) embryos until stage 25, they are not expressed in the male (26 degrees C) urinogenital system after stage 24. Subsequent experiments have identified both turtle proteins as heterogeneous nuclear ribonucleoprotein particles (hnRNPs). As several hnRNP proteins have specific RNA-binding sites and are involved in mRNA processing reactions, the 46K protein may mediate post-transcriptional control of specific RNA transcripts required for sexual differentiation in C. caretta.

Post-transcriptional and post-translational regulation of Bcl2

2010 ◽  
Vol 38 (6) ◽  
pp. 1571-1575 ◽  
Author(s):  
Shaun Willimott ◽  
Simon D. Wagner
Keyword(s):  
Translational Regulation ◽  
Transcriptional Control ◽  
Rna Binding ◽  
Constitutive Expression ◽  
Regulatory Elements ◽  
Therapeutic Approaches ◽  
Internal Ribosome Entry ◽  
Essential Function ◽  
Cellular Stresses ◽  
Bcl2 Expression

Bcl2 is an important pro-survival protein that has an essential function in normal immunity and whose constitutive expression leads to the development of lymphomas. Although transcriptional control of Bcl2 has been reported, increasing evidence suggests an important component of Bcl2 regulation is post-transcriptional. Phosphorylation of Bcl2 has been shown to enhance activity to allow response to extracellular growth-factor-mediated signals. Bcl2 mRNA contains regulatory elements in both its 5′- and 3′-UTRs (untranslated regions). An IRES (internal ribosome entry sequence) in the 5′-UTR permits continued translation in the presence of cellular stresses that reduce cap-dependent translation. The 3′-UTR of Bcl2 mRNA is 5.2 kb in length and contains multiple predicted miRNA (microRNA) and RNA-BP (RNA-binding protein)-binding sites. miR-15a and miR-16-1 have been found to inhibit Bcl2 expression in B-cells, whereas the RNA-BP nucleolin has been shown to increase Bcl2 expression by binding to the 3′-UTR and enhancing mRNA stability. Both decreased expression of miR-15a and miR-16-1 and increased nucleolin have been shown to be associated with increased Bcl2 expression and resistance to apoptosis in the common human disease, chronic lymphocytic leukaemia. miRNA-based therapeutic approaches to treat cancer are emerging. Bcl2 is highly regulated by miRNAs and is therefore an excellent candidate for such approaches.

Transcriptional derepression of the Saccharomyces cerevisiae HSP26 gene during heat shock

1990 ◽  
Vol 10 (12) ◽  
pp. 6362-6373
Author(s):  
R E Susek ◽  
S Lindquist
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Transcriptional Control ◽  
Critical Role ◽  
Constitutive Expression ◽  
Small Heat Shock Protein ◽  
Yeast Cells ◽  
Heat Shock Gene ◽  
General Mechanism ◽  
Regulatory Sequences

hsp26, the small heat shock protein of Saccharomyces cerevisiae, accumulates in response to heat and other types of stress. It also accumulates during the normal course of development, as cells enter stationary phase growth or begin to sporulate (S. Kurtz, J. Rossi, L. Petko, and S. Lindquist, Science 231:1154-1157, 1986). Analysis of deletion and insertion mutations demonstrated that transcriptional control plays a critical role in regulating HSP26 expression. The HSP26 promoter was found to be complex and appears to contain repressing elements as well as activating elements. Several upstream deletion mutations resulted in strong constitutive expression of HSP26. Furthermore, upstream sequences from the HSP26 gene repressed the constitutive expression of a heterologous heat shock gene. We propose that basal repression and heat-induced depression of transcription play major roles in regulating the expression of HSP26. None of the recombinant constructs that we analyzed separated cis-regulatory sequences responsible for heat shock regulation from those responsible for developmental regulation of HSP26. Depression of HSP26 transcription may be the general mechanism of HSP26 induction in yeast cells. This regulatory scheme is very different from that described for the regulation of most other heat shock genes.

scholarly journals Transcriptional derepression of the Saccharomyces cerevisiae HSP26 gene during heat shock.

1990 ◽  
Vol 10 (12) ◽  
pp. 6362-6373 ◽  
Author(s):  
R E Susek ◽  
S Lindquist
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Transcriptional Control ◽  
Critical Role ◽  
Constitutive Expression ◽  
Small Heat Shock Protein ◽  
Yeast Cells ◽  
Heat Shock Gene ◽  
General Mechanism ◽  
Regulatory Sequences

hsp26, the small heat shock protein of Saccharomyces cerevisiae, accumulates in response to heat and other types of stress. It also accumulates during the normal course of development, as cells enter stationary phase growth or begin to sporulate (S. Kurtz, J. Rossi, L. Petko, and S. Lindquist, Science 231:1154-1157, 1986). Analysis of deletion and insertion mutations demonstrated that transcriptional control plays a critical role in regulating HSP26 expression. The HSP26 promoter was found to be complex and appears to contain repressing elements as well as activating elements. Several upstream deletion mutations resulted in strong constitutive expression of HSP26. Furthermore, upstream sequences from the HSP26 gene repressed the constitutive expression of a heterologous heat shock gene. We propose that basal repression and heat-induced depression of transcription play major roles in regulating the expression of HSP26. None of the recombinant constructs that we analyzed separated cis-regulatory sequences responsible for heat shock regulation from those responsible for developmental regulation of HSP26. Depression of HSP26 transcription may be the general mechanism of HSP26 induction in yeast cells. This regulatory scheme is very different from that described for the regulation of most other heat shock genes.

scholarly journals Molecular and Cellular Mechanisms Underlying Temperature-Dependent Sex Determination in Turtles

2021 ◽  
pp. 1-9
Author(s):  
Horacio Merchant-Larios ◽  
Verónica Díaz-Hernández ◽  
Diego Cortez
Keyword(s):  
Animal Models ◽  
Sex Determination ◽  
Incubation Temperature ◽  
State Of The Art ◽  
Current Understanding ◽  
Temperature Dependent ◽  
Cellular Mechanisms ◽  
Male Phenotype ◽  
History Of ◽  
Reptilian Species

The discovery in mammals that fetal testes are required in order to develop the male phenotype inspired research efforts to elucidate the mechanisms underlying gonadal sex determination and differentiation in vertebrates. A pioneer work in 1966 that demonstrated the influence of incubation temperature on sexual phenotype in some reptilian species triggered great interest in the environment’s role as a modulator of plasticity in sex determination. Several chelonian species have been used as animal models to test hypotheses concerning the mechanisms involved in temperature-dependent sex determination (TSD). This brief review intends to outline the history of scientific efforts that corroborate our current understanding of the state-of-the-art in TSD using chelonian species as a reference.

scholarly journals Identification of Novel RNA Binding Proteins Influencing Circular RNA Expression in Hepatocellular Carcinoma

2021 ◽  
Vol 22 (14) ◽  
pp. 7477
Author(s):  
Rok Razpotnik ◽  
Petra Nassib ◽  
Tanja Kunej ◽  
Damjana Rozman ◽  
Tadeja Režen
Keyword(s):  
Hepatocellular Carcinoma ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Regulatory Protein ◽  
Circular Rna ◽  
Differentially Expressed ◽  
Circular Rnas ◽  
Bioinformatics Analyses ◽  
Published Evidence

Circular RNAs (circRNAs) are increasingly recognized as having a role in cancer development. Their expression is modified in numerous cancers, including hepatocellular carcinoma (HCC); however, little is known about the mechanisms of their regulation. The aim of this study was to identify regulators of circRNAome expression in HCC. Using publicly available datasets, we identified RNA binding proteins (RBPs) with enriched motifs around the splice sites of differentially expressed circRNAs in HCC. We confirmed the binding of some of the candidate RBPs using ChIP-seq and eCLIP datasets in the ENCODE database. Several of the identified RBPs were found to be differentially expressed in HCC and/or correlated with the overall survival of HCC patients. According to our bioinformatics analyses and published evidence, we propose that NONO, PCPB2, PCPB1, ESRP2, and HNRNPK are candidate regulators of circRNA expression in HCC. We confirmed that the knocking down the epithelial splicing regulatory protein 2 (ESRP2), known to be involved in the maintenance of the adult liver phenotype, significantly changed the expression of candidate circRNAs in a model HCC cell line. By understanding the systemic changes in transcriptome splicing, we can identify new proteins involved in the molecular pathways leading to HCC development and progression.

Characterization and primary structure of the poly(C)-binding heterogeneous nuclear ribonucleoprotein complex K protein

1992 ◽  
Vol 12 (1) ◽  
pp. 164-171
Author(s):  
M J Matunis ◽  
W M Michael ◽  
G Dreyfuss
Keyword(s):  
Hela Cells ◽  
Mammalian Cells ◽  
Binding Proteins ◽  
Rna Binding ◽  
Consensus Sequence ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Predicted Amino Acid Sequence ◽  
Cdna Clones ◽  
Hnrnp Proteins

At least 20 major proteins make up the ribonucleoprotein (RNP) complexes of heterogeneous nuclear RNA (hnRNA) in mammalian cells. Many of these proteins have distinct RNA-binding specificities. The abundant, acidic heterogeneous nuclear RNP (hnRNP) K and J proteins (66 and 64 kDa, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) are unique among the hnRNP proteins in their binding preference: they bind tenaciously to poly(C), and they are the major oligo(C)- and poly(C)-binding proteins in human HeLa cells. We purified K and J from HeLa cells by affinity chromatography and produced monoclonal antibodies to them. K and J are immunologically related and conserved among various vertebrates. Immunofluorescence microscopy with antibodies shows that K and J are located in the nucleoplasm. cDNA clones for K were isolated, and their sequences were determined. The predicted amino acid sequence of K does not contain an RNP consensus sequence found in many characterized hnRNP proteins and shows no extensive homology to sequences of any known proteins. The K protein contains two internal repeats not found in other known proteins, as well as GlyArgGlyGly and GlyArgGlyGlyPhe sequences, which occur frequently in many RNA-binding proteins. Overall, K represents a novel type of hnRNA-binding protein. It is likely that K and J play a role in the nuclear metabolism of hnRNAs, particularly for pre-mRNAs that contain cytidine-rich sequences.

scholarly journals Arginine Methyltransferases as Regulators of RNA-Binding Protein Activities in Pathogenic Kinetoplastids

2021 ◽  
Vol 8 ◽  
Author(s):  
Gustavo D. Campagnaro ◽  
Edward Nay ◽  
Michael J. Plevin ◽  
Angela K. Cruz ◽  
Pegine B. Walrad
Keyword(s):  
Gene Expression ◽  
Transcriptional Control ◽  
Rna Binding ◽  
Methylation Status ◽  
Regulation Of Gene Expression ◽  
Structural Features ◽  
Arginine Methylation ◽  
Diverse Range ◽  
Host Interaction ◽  
Intronless Genes

A large number of eukaryotic proteins are processed by single or combinatorial post-translational covalent modifications that may alter their activity, interactions and fate. The set of modifications of each protein may be considered a “regulatory code”. Among the PTMs, arginine methylation, catalyzed by protein arginine methyltransferases (PRMTs), can affect how a protein interacts with other macromolecules such as nucleic acids or other proteins. In fact, many RNA-binding (RBPs) proteins are targets of PRMTs. The methylation status of RBPs may affect the expression of their bound RNAs and impact a diverse range of physiological and pathological cellular processes. Unlike most eukaryotes, Kinetoplastids have overwhelmingly intronless genes that are arranged within polycistronic units from which mature mRNAs are generated by trans-splicing. Gene expression in these organisms is thus highly dependent on post-transcriptional control, and therefore on the action of RBPs. These genetic features make trypanosomatids excellent models for the study of post-transcriptional regulation of gene expression. The roles of PRMTs in controlling the activity of RBPs in pathogenic kinetoplastids have now been studied for close to 2 decades with important advances achieved in recent years. These include the finding that about 10% of the Trypanosoma brucei proteome carries arginine methylation and that arginine methylation controls Leishmania:host interaction. Herein, we review how trypanosomatid PRMTs regulate the activity of RBPs, including by modulating interactions with RNA and/or protein complex formation, and discuss how this impacts cellular and biological processes. We further highlight unique structural features of trypanosomatid PRMTs and how it contributes to their singular functionality.

scholarly journals MORE SEX-DETERMINATION MUTANTS OF CAENORHABDITIS ELEGANS

Genetics ◽  
1980 ◽  
Vol 96 (3) ◽  
pp. 649-664 ◽  
Author(s):  
Jonathan Hodgkin
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
X Chromosome ◽  
Constitutive Expression ◽  
Complementation Group ◽  
Sperm Production ◽  
Recessive Mutations ◽  
Her 2 ◽  
Map Location ◽  
Her Genes

ABSTRACT Sex determination in Caenorhabditis elegans is controlled by the X chromosome: autosome ratio, i.e. 2A;XX animals are hermaphrodite, and 2A;XO animals are male. A procedure for isolating 2A;XO animals that are transformed into hermaphrodites has been developed. Nine mutations causing this transformation have been obtained: eight are recessive, and all of these fall into a new autosomal complementation group, her-1 V. The remaining mutation (her-2) is dominant and has a genetic map location similar to that of tra-1 III. Recessive mutations of tra-1 cause the reverse transformation, transforming 2A;XX animals into males. Therefore, the her-2 mutation may result in constitutive expression of tra-1. Mutations in her-1 are without effect on XX animals, but the her-2 mutation prevents sperm production in both XX and XO animals, in addition to its effect on the sexual phenotype of XO animals. The epistatic relationships between tra and her genes are used to deduce a model for the action of these genes in controlling sex determination.

Riboregulators in plant development

2007 ◽  
Vol 35 (6) ◽  
pp. 1638-1642 ◽  
Author(s):  
P. Laporte ◽  
F. Merchan ◽  
B.B. Amor ◽  
S. Wirth ◽  
M. Crespi
Keyword(s):  
Large Scale ◽  
Transcriptional Control ◽  
Rna Binding ◽  
Bioinformatic Analysis ◽  
Nodule Development ◽  
Small Interfering Rnas ◽  
Cortical Cells ◽  
Protein Coding ◽  
Early Nodulin ◽  
Model Plant Arabidopsis Thaliana

npcRNA (non-protein-coding RNAs) are an emerging class of regulators, so-called riboregulators, and include a large diversity of small RNAs [miRNAs (microRNAs)/siRNAs (small interfering RNAs)] that are involved in various developmental processes in plants and animals. In addition, several other npcRNAs encompassing various transcript sizes (up to several kilobases) have been identified using different genomic approaches. Much less is known about the mechanism of action of these other classes of riboregulators also present in the cell. The organogenesis of nitrogen-fixing nodules in legume plants is initiated in specific root cortical cells that express the npcRNA MtENOD40 (Medicago truncatula early nodulin 40). We have identified a novel RBP (RNA-binding protein), MtRBP1 (M. truncatula RBP 1), which interacts with the MtENOD40 RNA, and is exported into the cytoplasm during legume nodule development in the region expressing MtENOD40. A direct involvement of the MtENOD40 RNA in the relocalization of this RBP into cytoplasmic granules could be demonstrated, revealing a new RNA function in the cell. To extend these results, we searched for npcRNAs in the model plant Arabidopsis thaliana whose genome is completely known. We have identified 86 novel npcRNAs from which 27 corresponded to antisense RNAs of known coding regions. Using a dedicated ‘macroarray’ containing these npcRNAs and a collection of RBPs, we characterized their regulation in different tissues and plants subjected to environmental stresses. Most of the npcRNAs showed high variations in gene expression in contrast with the RBP genes. Recent large-scale analysis of the sRNA component of the transcriptome revealed an enormous diversity of siRNAs/miRNAs in the Arabidopsis genome. Bioinformatic analysis revealed that 34 large npcRNAs are precursors of siRNAs/miRNAs. npcRNAs, which are a sensitive component of the transcriptome, may reveal novel riboregulatory mechanisms involved in post-transcriptional control of differentiation or environmental responses.

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