scholarly journals Alternatively spliced mRNA variants of chloroplast ascorbate peroxidase isoenzymes in spinach leaves

1999 ◽  
Vol 338 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Kazuya YOSHIMURA ◽  
Yukinori YABUTA ◽  
Masahiro TAMOI ◽  
Takahiro ISHIKAWA ◽  
Shigeru SHIGEOKA
Keyword(s):  
Ascorbate Peroxidase ◽  
Differential Splicing ◽  
Gene Encoding ◽  
S1 Nuclease ◽  
C Terminus ◽  
Mrna Variants ◽  
Alternatively Spliced ◽  
Splicing Efficiency ◽  
Spinach Leaves

We have previously shown that stromal and thylakoid-bound ascorbate peroxidase (APX) isoenzymes of spinach chloroplasts arise from a common pre-mRNA by alternative splicing in the C-terminus of the isoenzymes [Ishikawa, Yoshimura, Tamoi, Takeda and Shigeoka (1997) Biochem. J. 328, 795–800]. To explore the production of mature, functional mRNA encoding chloroplast APX isoenzymes, reverse transcriptase-mediated PCR and S1 nuclease protection analysis were performed with poly(A)+ RNA or polysomal RNA from spinach leaves. As a result, four mRNA variants, one form of thylakoid-bound APX (tAPX-I) and three forms of stromal APX (sAPX-I, sAPX-II and sAPX-III), were identified. The sAPX-I and sAPX-III mRNA species were generated through the excision of intron 11; they encoded the previously identified sAPX protein. Interestingly, the sAPX-II mRNA was generated by the insertion of intron 11 between exons 11 and 12. The use of this insertional sequence was in frame with the coding sequence and would lead to the production of a novel isoenzyme containing a C-terminus in which a seven-residue sequence replaced the last residue of the previously identified sAPX. The recombinant novel enzyme expressed in Escherichia coli showed the same enzymic properties (except for molecular mass) as the recombinant sAPX from the previously identified sAPX-I mRNA, suggesting that the protein translated from the sAPX-II mRNA is functional as a soluble APX in vivo. The S1 nuclease protection analysis showed that the expression levels of mRNA variants for sAPX and tAPX isoenzymes are in nearly equal quantities throughout the spinach leaves grown under normal conditions. The present results demonstrate that the expression of chloroplast APX isoenzymes is regulated by a differential splicing efficiency that is dependent on the 3´-terminal processing of ApxII, the gene encoding the chloroplast APX isoenzymes.

scholarly journals Alternatively spliced mRNA variants of chloroplast ascorbate peroxidase isoenzymes in spinach leaves

1999 ◽  
Vol 338 (1) ◽  
pp. 41 ◽  
Author(s):  
Kazuya YOSHIMURA ◽  
Yukinori YABUTA ◽  
Masahiro TAMOI ◽  
Takahiro ISHIKAWA ◽  
Shigeru SHIGEOKA
Keyword(s):  
Ascorbate Peroxidase ◽  
Peroxidase Isoenzymes ◽  
Mrna Variants ◽  
Alternatively Spliced ◽  
Spinach Leaves

scholarly journals Two Alternatively Spliced Transcripts from the Drosophila period Gene Rescue Rhythms Having Different Molecular and Behavioral Characteristics

1998 ◽  
Vol 18 (11) ◽  
pp. 6505-6514 ◽  
Author(s):  
Yuzhong Cheng ◽  
Barbara Gvakharia ◽  
Paul E. Hardin
Keyword(s):  
Type A ◽  
Behavioral Characteristics ◽  
Cdna Clones ◽  
Type B ◽  
Differential Splicing ◽  
Rnase Protection ◽  
Period Gene ◽  
Alternatively Spliced ◽  
Transgenic Flies

ABSTRACT The period (per) and timeless(tim) genes encode key components of the circadian oscillator in Drosophila melanogaster. The pergene is thought to encode three transcripts via differential splicing (types A, B, and C) that give rise to three proteins. Since the threeper mRNA types were based on the analysis of cDNA clones, we tested whether these mRNA types were present in vivo by RNase protection assays and reverse transcriptase-mediated PCR. The results show that per generates two transcript types that differ only by the presence (type A) or absence (type B′) of an alternative intron in the 3′ untranslated region. Transgenic flies containing transgenes that produce only type B′ transcripts (perB′ ), type A transcripts (perA ), or both transcripts (perG ) rescue locomotor activity rhythms with average periods of 24.7, 25.4, and 24.4 h, respectively. Although no appreciable differences in type A and type B′ mRNA cycling were observed, a slower accumulation of PER in flies making only type A transcripts suggests that the intron affects the translation ofper mRNA.

scholarly journals Murine Leukemia Virus P50 Protein Counteracts APOBEC3 by Blocking Its Packaging

2020 ◽  
Vol 94 (18) ◽  
Author(s):  
Wenming Zhao ◽  
Charbel Akkawi ◽  
Marylène Mougel ◽  
Susan R. Ross
Keyword(s):  
Cell Line ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Stable Cell Line ◽  
Host Restriction ◽  
C Terminus ◽  
Alternatively Spliced ◽  
Apobec3 Proteins ◽  
Murine Leukemia

ABSTRACT Apolipoprotein B editing enzyme, catalytic polypeptide 3 (APOBEC3) family members are cytidine deaminases that play important roles in intrinsic responses to retrovirus infection. Complex retroviruses like human immunodeficiency virus type 1 (HIV-1) encode the viral infectivity factor (Vif) protein to counteract APOBEC3 proteins. Vif induces degradation of APOBEC3G and other APOBEC3 proteins and thereby prevents their packaging into virions. It is not known if murine leukemia virus (MLV) encodes a Vif-like protein. Here, we show that the MLV P50 protein, produced from an alternatively spliced gag RNA, interacts with the C terminus of mouse APOBEC3 and prevents its packaging without causing its degradation. By infecting APOBEC3 knockout (KO) and wild-type (WT) mice with Friend or Moloney MLV P50-deficient viruses, we found that APOBEC3 restricts the mutant viruses more than WT viruses in vivo. Replication of P50-mutant viruses in an APOBEC3-expressing stable cell line was also much slower than that of WT viruses, and overexpressing P50 in this cell line enhanced mutant virus replication. Thus, MLV encodes a protein, P50, that overcomes APOBEC3 restriction by preventing its packaging into virions. IMPORTANCE MLV has existed in mice for at least a million years, in spite of the existence of host restriction factors that block infection. Although MLV is considered a simple retrovirus compared to lentiviruses, it does encode proteins generated from alternatively spliced RNAs. Here, we show that P50, generated from an alternatively spliced RNA encoded in gag, counteracts APOBEC3 by blocking its packaging. MLV also encodes a protein, glycoGag, that increases capsid stability and limits APOBEC3 access to the reverse transcription complex (RTC). Thus, MLV has evolved multiple means of preventing APOBEC3 from blocking infection, explaining its survival as an infectious pathogen in mice.

scholarly journals Establishing F1A-CreERT2 Mice to Trace Fgf1 Expression in Adult Mouse Cardiomyocytes

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 121
Author(s):  
Yi-Chao Hsu ◽  
Yu-Fen Chung ◽  
Mei-Shu Chen ◽  
Chi-Kuang Wang ◽  
Si-Tse Jiang ◽  
...  
Keyword(s):  
Troponin T ◽  
Lineage Tracing ◽  
Mouse Line ◽  
Protein Coding ◽  
Physiological Processes ◽  
Mrna Variants ◽  
Alternatively Spliced

Fibroblast growth factor 1 (FGF1) regulates many biological and physiological processes. In mice, Fgf1 gene contains at least three upstream promoters and are alternatively spliced to the first protein coding exon, giving rise to different Fgf1 mRNA variants (1A, 1B and 1G). Among them, the Fgf1A transcript is predominantly expressed in the heart. FGF1 can induce cardiomyocyte regeneration and cardiogenesis in vitro and in vivo. Here, we generated a novel mouse line using the Fgf1A promoter (F1A) driving the expression of the inducible Cre recombinase (CreERT2). We firstly demonstrated that the highest mRNA expression of CreERT2 were detected in the heart specifically of F1A-CreERT2 mice, similar to that of Fgf1A mRNA. The F1A-CreERT2 mice were crossed with ROSA26 mice, and the F1 mice were analyzed. The LacZ-positive signals were detected exclusively in the heart after tamoxifen administration. The CreERT2-mediated recombination in the tissues is monitored through LacZ-positive signals, indicating the in situ localization of F1A-positive cells. Consistently, these F1A-positive cells with RFP-positive signals or LacZ-positive blue signals were co-localized with cardiomyocytes expressing cardiac troponin T, suggesting cardiomyocyte-specific activation of Fgf1A promoter. Our data suggested that the F1A-CreERT2 mouse line could be used for time-dependent and lineage tracing of Fgf1A-expressing cells in vivo.

scholarly journals The C terminus of lettuce mosaic potyvirus cylindrical inclusion helicase interacts with the viral VPg and with lettuce translation eukaryotic initiation factor 4E

2012 ◽  
Vol 93 (1) ◽  
pp. 184-193 ◽  
Author(s):  
G. Tavert-Roudet ◽  
A. Abdul-Razzak ◽  
B. Doublet ◽  
J. Walter ◽  
T. Delaunay ◽  
...  
Keyword(s):  
Interaction Network ◽  
Translation Initiation Factor ◽  
Bimolecular Fluorescence Complementation ◽  
Cylindrical Inclusion ◽  
Initiation Factor ◽  
Gene Encoding ◽  
Resistance Breaking ◽  
C Terminus

Recessive resistance to lettuce mosaic virus (LMV) is conferred in lettuce by the mo1 gene, encoding the eukaryotic translation initiation factor 4E (eIF4E). The C terminus of the viral cylindrical inclusion helicase (CI-Cter), together with the VPg, is involved directly in overcoming mo1 resistance. In this study, recombinant LMV VPg and CI-Cter proteins from wild-type or resistance-breaking isolates were expressed and purified from Escherichia coli. The allelic forms of eIF4E from susceptible or resistant lettuce cultivars were produced similarly and these proteins were used in ELISA-based assays to demonstrate the in vitro binding of the various forms of LMV CI-Cter to both lettuce eIF4E and LMV VPg proteins. All combinations tested displayed significant and specific interactions, and the interaction between the C-terminal part of the LMV CI and eIF4E was confirmed in vivo in bimolecular fluorescence complementation assays. Higher interaction signals for both CI–eIF4E and CI–VPg were observed for LMV-E, indicating that the eIF4E interaction network involving CI and VPg appears to be stronger in the case of this resistance-breaking isolate. This could suggest the need for a minimal interaction threshold for infection success in resistant lettuce, but more precise measurement of the interaction parameters linking eIF4E, VPg and CI is needed in order to reinforce such a hypothesis.

SAC3B is a target of CML19, the centrin 2 of Arabidopsis thaliana

2020 ◽  
Vol 477 (1) ◽  
pp. 173-189 ◽  
Author(s):  
Marco Pedretti ◽  
Carolina Conter ◽  
Paola Dominici ◽  
Alessandra Astegno
Keyword(s):  
Excision Repair ◽  
Complex Structure ◽  
Binding Motif ◽  
C Terminus ◽  
Repair Protein ◽  
Nucleotide Excision ◽  
Ef Hand ◽  
Molecular Determinants ◽  
Structure In Solution

Arabidopsis centrin 2, also known as calmodulin-like protein 19 (CML19), is a member of the EF-hand superfamily of calcium (Ca2+)-binding proteins. In addition to the notion that CML19 interacts with the nucleotide excision repair protein RAD4, CML19 was suggested to be a component of the transcription export complex 2 (TREX-2) by interacting with SAC3B. However, the molecular determinants of this interaction have remained largely unknown. Herein, we identified a CML19-binding site within the C-terminus of SAC3B and characterized the binding properties of the corresponding 26-residue peptide (SAC3Bp), which exhibits the hydrophobic triad centrin-binding motif in a reversed orientation (I8W4W1). Using a combination of spectroscopic and calorimetric experiments, we shed light on the SAC3Bp–CML19 complex structure in solution. We demonstrated that the peptide interacts not only with Ca2+-saturated CML19, but also with apo-CML19 to form a protein–peptide complex with a 1 : 1 stoichiometry. Both interactions involve hydrophobic and electrostatic contributions and include the burial of Trp residues of SAC3Bp. However, the peptide likely assumes different conformations upon binding to apo-CML19 or Ca2+-CML19. Importantly, the peptide dramatically increases the affinity for Ca2+ of CML19, especially of the C-lobe, suggesting that in vivo the protein would be Ca2+-saturated and bound to SAC3B even at resting Ca2+-levels. Our results, providing direct evidence that Arabidopsis SAC3B is a CML19 target and proposing that CML19 can bind to SAC3B through its C-lobe independent of a Ca2+ stimulus, support a functional role for these proteins in TREX-2 complex and mRNA export.

scholarly journals A Peptide Found in Human Serum, Derived from the C-Terminus of Albumin, Shows Antifungal Activity In Vitro and In Vivo

2020 ◽  
Vol 8 (10) ◽  
pp. 1627
Author(s):  
Tecla Ciociola ◽  
Pier Paolo Zanello ◽  
Tiziana D’Adda ◽  
Serena Galati ◽  
Stefania Conti ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Human Serum ◽  
Fungicidal Activity ◽  
Galleria Mellonella ◽  
Serum Proteins ◽  
Morphological Alterations ◽  
C Terminus ◽  
Different Sources

The growing problem of antimicrobial resistance highlights the need for alternative strategies to combat infections. From this perspective, there is a considerable interest in natural molecules obtained from different sources, which are shown to be active against microorganisms, either alone or in association with conventional drugs. In this paper, peptides with the same sequence of fragments, found in human serum, derived from physiological proteins, were evaluated for their antifungal activity. A 13-residue peptide, representing the 597–609 fragment within the albumin C-terminus, was proved to exert a fungicidal activity in vitro against pathogenic yeasts and a therapeutic effect in vivo in the experimental model of candidal infection in Galleria mellonella. Studies by confocal microscopy and transmission and scanning electron microscopy demonstrated that the peptide penetrates and accumulates in Candida albicans cells, causing gross morphological alterations in cellular structure. These findings add albumin to the group of proteins, which already includes hemoglobin and antibodies, that could give rise to cryptic antimicrobial fragments, and could suggest their role in anti-infective homeostasis. The study of bioactive fragments from serum proteins could open interesting perspectives for the development of new antimicrobial molecules derived by natural sources.

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