scholarly journals Phenotypic effects from the expression of a deregulated AtGAD1 transgene and GABA pathway suppression mutants in maize

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0259365
Author(s):  
Rajani M. S ◽  
Mohamed F. Bedair ◽  
Hong Li ◽  
Stephen M. G. Duff
Keyword(s):  
Growth Conditions ◽  
Catabolic Pathway ◽  
Transport Pathway ◽  
Protein Amino Acid ◽  
Developmental Defects ◽  
Gaba Transport ◽  
Gaba A ◽  
Maize Plants ◽  
And Function ◽  
Gad Activity

Glutamate decarboxylase (GAD; EC 4.1.1.15) catalyzes the irreversible decarboxylation of glutamate to produce γ-aminobutyric acid (GABA); a ubiquitous non-protein amino acid involved in the regulation of several aspects of plant metabolism and physiology. To study the function of GAD and GABA in maize, we have; 1) introduced native and deregulated forms of AtGAD1 into maize with the intent of increasing the synthesis of GABA and 2) introduced constructs into maize designed to suppress the activity of several GABA shunt, GABA transport and GABA pathway genes. Maize plants expressing the deregulated AtGAD1 exhibit a severe chlorosis and retarded growth phenotype and have high levels of GABA, and Ca++/CaM-independent GAD activity. Plants expressing the suppression constructs for GABA biosynthetic and transport pathway genes had no observable phenotype whereas a knockout of GABA catabolic pathway genes led to growth and developmental defects under standard growth conditions. The implications of this study to our understanding of the action and function of GABA and GAD in crops are discussed.

scholarly journals Concentration-dependent lamin assembly and its roles in the localization of other nuclear proteins

2014 ◽  
Vol 25 (8) ◽  
pp. 1287-1297 ◽  
Author(s):  
Yuxuan Guo ◽  
Youngjo Kim ◽  
Takeshi Shimi ◽  
Robert D. Goldman ◽  
Yixian Zheng
Keyword(s):  
Nuclear Lamina ◽  
Nuclear Pore ◽  
Lamin A ◽  
Nuclear Pore Complexes ◽  
Developmental Defects ◽  
Protein Levels ◽  
Lamin B1 ◽  
Mouse Cells ◽  
Pore Complexes ◽  
And Function

The nuclear lamina (NL) consists of lamin polymers and proteins that bind to the polymers. Disruption of NL proteins such as lamin and emerin leads to developmental defects and human diseases. However, the expression of multiple lamins, including lamin-A/C, lamin-B1, and lamin-B2, in mammals has made it difficult to study the assembly and function of the NL. Consequently, it has been unclear whether different lamins depend on one another for proper NL assembly and which NL functions are shared by all lamins or are specific to one lamin. Using mouse cells deleted of all or different combinations of lamins, we demonstrate that the assembly of each lamin into the NL depends primarily on the lamin concentration present in the nucleus. When expressed at sufficiently high levels, each lamin alone can assemble into an evenly organized NL, which is in turn sufficient to ensure the even distribution of the nuclear pore complexes. By contrast, only lamin-A can ensure the localization of emerin within the NL. Thus, when investigating the role of the NL in development and disease, it is critical to determine the protein levels of relevant lamins and the intricate shared or specific lamin functions in the tissue of interest.

scholarly journals HC-Pro protein of sugar cane mosaic virus interacts specifically with maize ferredoxin-5 in vitro and in planta

2008 ◽  
Vol 89 (8) ◽  
pp. 2046-2054 ◽  
Author(s):  
Yu-Qin Cheng ◽  
Zhong-Mei Liu ◽  
Jian Xu ◽  
Tao Zhou ◽  
Meng Wang ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Sugar Cane ◽  
Transit Peptide ◽  
Viral Disease ◽  
Middle Part ◽  
Symptom Development ◽  
In Planta ◽  
Maize Plants ◽  
And Function

Symptom development of a plant viral disease is a result of molecular interactions between the virus and its host plant; thus, the elucidation of specific interactions is a prerequisite to reveal the mechanism of viral pathogenesis. Here, we show that the chloroplast precursor of ferredoxin-5 (Fd V) from maize (Zea mays) interacts with the multifunctional HC-Pro protein of sugar cane mosaic virus (SCMV) in yeast, Nicotiana benthamiana cells and maize protoplasts. Our results demonstrate that the transit peptide rather than the mature protein of Fd V precursor could interact with both N-terminal (residues 1–100) and C-terminal (residues 301–460) fragments, but not the middle part (residues 101–300), of HC-Pro. In addition, SCMV HC-Pro interacted only with Fd V, and not with the other two photosynthetic ferredoxin isoproteins (Fd I and Fd II) from maize plants. SCMV infection significantly downregulated the level of Fd V mRNA in maize plants; however, no obvious changes were observed in levels of Fd I and Fd II mRNA. These results suggest that SCMV HC-Pro interacts specifically with maize Fd V and that this interaction may disturb the post-translational import of Fd V into maize bundle-sheath cell chloroplasts, which could lead to the perturbation of chloroplast structure and function.

Specific ablation of the nidogen-binding site in the laminin γ1 chain interferes with kidney and lung development

Development ◽  
2002 ◽  
Vol 129 (11) ◽  
pp. 2711-2722 ◽  
Author(s):  
Michael Willem ◽  
Nicolai Miosge ◽  
Willi Halfter ◽  
Neil Smyth ◽  
Iris Jannetti ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Binding Site ◽  
Lung Development ◽  
Collagen Type Iv ◽  
Developmental Defects ◽  
Type Iv ◽  
And Function ◽  
Kidney Morphogenesis ◽  
Nidogen 1

Basement membrane assembly is of crucial importance in the development and function of tissues and during embryogenesis. Nidogen 1 was thought to be central in the assembly processes, connecting the networks formed by collagen type IV and laminins, however, targeted inactivation of nidogen 1 resulted in no obvious phenotype. We have now selectively deleted the sequence coding for the 56 amino acid nidogen-binding site, γ1III4, within the Lamc1 gene by gene targeting. Here, we show that mice homozygous for the deletion die immediately after birth, showing renal agenesis and impaired lung development. These developmental defects were attributed to locally restricted ruptures in the basement membrane of the elongating Wolffian duct and of alveolar sacculi. These data demonstrate that an interaction between two basement membrane proteins is required for early kidney morphogenesis in vivo.

scholarly journals Localization and function of ATP and GABA A receptors expressed by nociceptors and other postnatal sensory neurons in rat

2003 ◽  
Vol 549 (1) ◽  
pp. 131-142 ◽  
Author(s):  
Charalampos Labrakakis ◽  
Chi‐Kun Tong ◽  
Tamily Weissman ◽  
Carole Torsney ◽  
Amy B. MacDermott
Keyword(s):  
Sensory Neurons ◽  
Gaba A ◽  
And Function

scholarly journals Changes in the acyl lipid composition of photosynthetic bacteria grown under photosynthetic and non-photosynthetic conditions

1979 ◽  
Vol 181 (2) ◽  
pp. 339-345 ◽  
Author(s):  
Nicholas J. Russell ◽  
John L. Harwood
Keyword(s):  
Fatty Acids ◽  
Photosynthetic Bacteria ◽  
Rhodospirillum Rubrum ◽  
Relative Proportion ◽  
Photosynthetic Apparatus ◽  
Growth Conditions ◽  
Rhodopseudomonas Capsulata ◽  
Rhodopseudomonas Sphaeroides ◽  
Acyl Lipids ◽  
And Function

The acyl lipids and their constituent fatty acids were studied in the photosynthetic bacteria Rhodospirillum rubrum, Rhodopseudomonas capsulata and Rhodopseudomonas sphaeroides, which were grown under photosynthetic and non-photosynthetic conditions. The major lipids were found to be phosphatidylethanolamine, phosphatidylglycerol and cardiolipin in each bacterium. The two Rhodopseudomonas species also contained significant quantities of phosphatidylcholine. Other acyl lipids accounted for less than 10% of the total. On changing growth conditions from non-photosynthetic to photosynthetic a large increase in the relative proportion of phosphatidylglycerol was seen at the expense of phosphatidyl-ethanolamine. In Rhodospirillum rubrum the fatty acids of the major phospholipids showed an increase in the proportion of palmitate and stearate and a decrease in palmitoleate and vaccenate on changing growth conditions to photosynthetic. In contrast, the exceptionally high levels (>80%) of vaccenate in individual phospholipids of Rhodopseudomonas capsulata and Rhodopseudomonas sphaeroides were unaffected by changing growth conditions to photosynthetic. Analysis of the lipids of chromatophores, isolated from the three bacteria, showed that these preparations were enriched in phosphatidylglycerol. The large increase in this phospholipid, seen during growth under photosynthetic conditions, appeared, therefore, to be due to a proliferation of chromatophore membranes. Possible roles for acyl lipids in the formation and function of the photosynthetic apparatus of bacteria are discussed.

scholarly journals A sart1 Zebrafish Mutant Results in Developmental Defects in the Central Nervous System

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2340
Author(s):  
Hannah E. Henson ◽  
Michael R. Taylor
Keyword(s):  
Central Nervous System ◽  
Cell Death ◽  
Nervous System ◽  
Developmental Defects ◽  
Whole Exome ◽  
The Central Nervous System ◽  
And Function ◽  
Upregulated Genes ◽  
The Brain

The spliceosome consists of accessory proteins and small nuclear ribonucleoproteins (snRNPs) that remove introns from RNA. As splicing defects are associated with degenerative conditions, a better understanding of spliceosome formation and function is essential. We provide insight into the role of a spliceosome protein U4/U6.U5 tri-snRNP-associated protein 1, or Squamous cell carcinoma antigen recognized by T-cells (Sart1). Sart1 recruits the U4.U6/U5 tri-snRNP complex to nuclear RNA. The complex then associates with U1 and U2 snRNPs to form the spliceosome. A forward genetic screen identifying defects in choroid plexus development and whole-exome sequencing (WES) identified a point mutation in exon 12 of sart1 in Danio rerio (zebrafish). This mutation caused an up-regulation of sart1. Using RNA-Seq analysis, we identified additional upregulated genes, including those involved in apoptosis. We also observed increased activated caspase 3 in the brain and eye and down-regulation of vision-related genes. Although splicing occurs in numerous cells types, sart1 expression in zebrafish was restricted to the brain. By identifying sart1 expression in the brain and cell death within the central nervous system (CNS), we provide additional insights into the role of sart1 in specific tissues. We also characterized sart1’s involvement in cell death and vision-related pathways.

scholarly journals A role for Gle1, a regulator of DEAD-box RNA helicases, at centrosomes and basal bodies

2017 ◽  
Vol 28 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Li-En Jao ◽  
Abdalla Akef ◽  
Susan R. Wente
Keyword(s):  
Mrna Export ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Rna Helicases ◽  
Microtubule Organization ◽  
Developmental Defects ◽  
Dead Box ◽  
Pericentriolar Material ◽  
Pore Complexes ◽  
And Function

Control of organellar assembly and function is critical to eukaryotic homeostasis and survival. Gle1 is a highly conserved regulator of RNA-dependent DEAD-box ATPase proteins, with critical roles in both mRNA export and translation. In addition to its well-defined interaction with nuclear pore complexes, here we find that Gle1 is enriched at the centrosome and basal body. Gle1 assembles into the toroid-shaped pericentriolar material around the mother centriole. Reduced Gle1 levels are correlated with decreased pericentrin localization at the centrosome and microtubule organization defects. Of importance, these alterations in centrosome integrity do not result from loss of mRNA export. Examination of the Kupffer’s vesicle in Gle1-depleted zebrafish revealed compromised ciliary beating and developmental defects. We propose that Gle1 assembly into the pericentriolar material positions the DEAD-box protein regulator to function in localized mRNA metabolism required for proper centrosome function.

scholarly journals N-linked glycosylation enzymes in the diatom Thalassiosira oceanica exhibit a diel cycle in transcript abundance and favor for NXT-type sites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joerg Behnke ◽  
Alejandro M. Cohen ◽  
Julie LaRoche
Keyword(s):  
Cell Biology ◽  
Biochemical Characterization ◽  
Solid Phase ◽  
Transcript Abundance ◽  
Growth Conditions ◽  
Iron Starvation ◽  
Glycosylation Sites ◽  
Glycosylation Pathway ◽  
And Function

AbstractN-linked glycosylation is a posttranslational modification affecting protein folding and function. The N-linked glycosylation pathway in algae is poorly characterized, and further knowledge is needed to understand the cell biology of algae and the evolution of N-linked glycosylation. This study investigated the N-linked glycosylation pathway in Thalassiosira oceanica, an open ocean diatom adapted to survive at growth-limiting iron concentrations. Here we identified and annotated the genes coding for the essential enzymes involved in the N-linked glycosylation pathway of T. oceanica. Transcript levels for genes coding for calreticulin, oligosaccharyltransferase (OST), N-acetylglucosaminyltransferase (GnT1), and UDP-glucose glucosyltransferase (UGGT) under high- and low-iron growth conditions revealed diel transcription patterns with a significant decrease of calreticulin and OST transcripts under iron-limitation. Solid-phase extraction of N-linked glycosylated peptides (SPEG) revealed 118 N-linked glycosylated peptides from cells grown in high- and low-iron growth conditions. The identified peptides had 81% NXT-type motifs, with X being any amino acids except proline. The presence of N-linked glycosylation sites in the iron starvation-induced protein 1a (ISIP1a) confirmed its predicted topology, contributing to the biochemical characterization of ISIP1 proteins. Analysis of extensive oceanic gene databases showed a global distribution of calreticulin, OST, and UGGT, reinforcing the importance of glycosylation in microalgae.

Use of mutant RNAs in studies on yeast 5S rRNA structure and function

1991 ◽  
Vol 69 (4) ◽  
pp. 217-222 ◽  
Author(s):  
Ross N. Nazar ◽  
Don I. Van Ryk ◽  
Yoon Lee ◽  
C. David Guyer
Keyword(s):  
Structural Changes ◽  
Growth Conditions ◽  
5S Rrna ◽  
Rrna Genes ◽  
Shuttle Vectors ◽  
5S Rrna Genes ◽  
And Function ◽  
Optimized Conditions ◽  
Rna Concentration

The expression of mutant yeast 5S rRNA genes in vivo is reviewed as a basis for further studies on the structure, function, and regulation of the ribosomal 5S rRNA. Specific base substitutions, insertions, or deletions can result in substantial structural changes which can be detected readily by gel electrophoresis, permitting the assay of mutant RNA synthesis and utilization. Furthermore, the use of high and low copy shuttle vectors, as well as alternate growth conditions, permits a wide adjustment of the mutant RNA concentration. Under optimized conditions more than 80% of the cell's RNA can be replaced with mutant molecules. The application of this strategy to studies on the biosynthesis and structure of the 5S rRNA are demonstrated through recently isolated mutations.Key words: site-specific mitogenesis, 5S RNA, ribosomes, yeast transformation.

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