Three new nuclear genes, sigD, sigE and sigF, encoding putative plastid RNA polymerase σ factors in Arabidopsis thaliana

Fujiwara, Makoto; Nagashima, Akitomo; Kanamaru, Kengo; Tanaka, Kan; Takahashi, Hideo

doi:10.1016/s0014-5793(00)01965-7

Cited by 88 publications

(90 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If this is the case, the SIG5 gene should be expressed in reproductive tissues in wild-type plants. Previously published analysis of SIG5 expression detected SIG5 transcripts in whole 12-d-old seedlings that had been ground up for RNA extraction (Fujiwara et al, 2000) and in rosette leaves of 4-week-old plants (Tsunoyama et al, 2002). Expression of SIG5 in rosette leaves agrees with the previously proposed role for AtSig5 in chloroplast gene expression.…”

Section: Atsig5 Accumulates In Reproductive Tissues Of Wildtype Arabisupporting

confidence: 79%

“…Therefore, it is assumed (although not yet experimentally demonstrated) that these nucleus-encoded plant -factors assemble in plastids with the PEP RNA polymerase to effect promoter recognition and transcription initiation. Consistent with this model, many plant -factors contain transit peptides capable of targeting the proteins into chloroplasts (Isono et al, 1997;Kanamaru et al, 1999;Lahiri et al, 1999;Fujiwara et al, 2000;Lahiri and Allison, 2000). Interestingly, the maize -factor, ZmSig2B, accumulates not only in chloroplasts but also in mitochondria, and contains an NH 2 -terminal sequence able to target fused green fluorescent protein (GFP) into mitochondria in transient expression assays (Beardslee et al, 2002).…”

mentioning

confidence: 81%

“…To determine whether AtSig5 also accumulates in reproductive tissues, we did immunoblots on both vegetative and reproductive plant organs using an antibody raised against the NH 2 -terminal region of AtSig5. Because the NH 2 terminus of AtSig5 is not conserved with the other Arabidopsis -factors (Fujiwara et al, 2000), this antibody is specific for the AtSig5 protein. Immunoblot analysis detected a band of the M r predicted for AtSig5 (approximately 58 kD) in rosette leaves, stems, immature siliques, and flowers, but not in roots (Fig.…”

Section: Atsig5 Accumulates In Reproductive Tissues Of Wildtype Arabimentioning

confidence: 99%

“…It has previously been noted (Fujiwara et al, 2000) that SIG5 has two potential in-frame AUG translational start codons, one (M1) located within intron 1, and the other (M2) located 75 bp downstream within exon 2 (diagrammed in Fig. 5A; sequence shown by Fujiwara et al [2000]).…”

Section: Sig5 Transcripts Are Differentially Processed In Leaf and Flmentioning

confidence: 99%

“…The SIG5 gene is unique in other ways. In phylogenetic analyses, SIG5 does not cluster closely with the other plant -factors but appears to form its own branch (Allison, 2000;Fujiwara et al, 2000). Moreover, the SIG5 gene does not exhibit any of the conserved intron sites that are shared by the other five Arabidopsis -factor genes (Fujiwara et al, 2000).…”

mentioning

confidence: 90%

See 4 more Smart Citations

AtSig5 Is an Essential Nucleus-Encoded Arabidopsis σ-Like Factor

2003

View full text Add to dashboard Cite

Transcription of chloroplast genes is subject to control by nucleus-encoded proteins. The chloroplast-encoded RNA polymerase (PEP) is a eubacterial-type RNA polymerase that is presumed to assemble with nucleus-encoded -factors mediating promoter recognition. Recently, families of -factor genes have been identified in several plants including Arabidopsis. One of these genes, Arabidopsis SIG5, encodes a -factor, AtSig5, which is phylogenetically distinct from the other family members. To investigate the role of this plant -factor, two different insertional alleles of the SIG5 gene were identified and characterized. Heterozygous mutant plants showed no visible leaf phenotype, but exhibited siliques containing aborted embryos and unfertilized ovules. Our inability to recover plants homozygous for a SIG5 gene disruption indicates that SIG5 is an essential gene. SIG5 transcripts accumulate in flower tissues, consistent with a role for AtSig5 protein in reproduction. Therefore, SIG5 encodes an essential member of the Arabidopsis -factor family that plays a role in plant reproduction in addition to its previously proposed role in leaf chloroplast gene expression.Transcription of plant mitochondrial and plastid genomes relies on nucleus-encoded RNA polymerases resembling those of the T3 and T7 bacteriophage, as well as promoter selectivity factors for these enzymes (for review, see Hess and Bö rner, 1999;Liere and Maliga, 2001). In addition, plastids, but not mitochondria, require an organelle-encoded RNA polymerase (PEP) for transcription of many genes on the organelle genome (Allison and Maliga, 1996;Hajdukiewicz et al., 1997;Serino and Maliga, 1998). PEP is similar in structure to Escherichia coli RNA polymerase and, like the eubacterial enzyme, is thought to assemble with -factors to achieve promoter-specific transcription initiation. Although the subunits of the PEP catalytic core are plastidencoded, the putative promoter-specificity -factors for PEP are encoded in the plant nucleus. Therefore, even the organelle-encoded transcription machinery is subject to nuclear control.Recently, -factor gene families containing as many as six members have been identified in several plant species including Arabidopsis and maize (Zea mays; for review, see Allison, 2000). Within a species, the sigma-like proteins share approximately 35% overall amino acid sequence identity and contain the conserved domains found in the principal -factors of all eubacteria (Helmann and Chamberlin, 1988). Genetic analyses of the eubacterial -factors, as well as more recent structural studies, have supported the importance of these conserved domains in such eubacterial transcription functions as promoter recognition, interaction with the RNA polymerase core enzyme, and transcription initiation (Gross et al., 1998;Burgess and Anthony, 2001;Campbell et al., 2002;Murakami et al., 2002). The conservation of primary structure among plant and eubacterial -factors is sufficiently high to permit recombinant plant -factors to function with E. coli core RNA po...

show abstract

Section: Atsig5 Accumulates In Reproductive Tissues Of Wildtype Arabisupporting

confidence: 79%

mentioning

confidence: 81%

Section: Atsig5 Accumulates In Reproductive Tissues Of Wildtype Arabimentioning

confidence: 99%

Section: Sig5 Transcripts Are Differentially Processed In Leaf and Flmentioning

confidence: 99%

mentioning

confidence: 90%

See 3 more Smart Citations

AtSig5 Is an Essential Nucleus-Encoded Arabidopsis σ-Like Factor

2003

View full text Add to dashboard Cite

show abstract

Cryptochrome 2 extensively regulates transcription of the chloroplast genome in tomato

Facella

Carbone

Placido³

et al. 2017

FEBS Open Bio

View full text Add to dashboard Cite

Light plays a key role in the regulation of many physiological processes required for plant and chloroplast development. Plant cryptochromes (crys) play an important role in monitoring, capturing, and transmitting the light stimuli. In this study, we analyzed the effects of CRY2 overexpression on transcription of tomato chloroplast genome by a tiling array, containing about 90 000 overlapping probes (5‐nucleotide resolution). We profiled transcription in leaves of wild‐type and CRY2‐overexpressing plants grown in a diurnal cycle, to generate a comprehensive map of chloroplast transcription and to monitor potential specific modulations of the chloroplast transcriptome induced by the overexpression of CRY2. Our results demonstrate that CRY2 is a master gene of transcriptional regulation in the tomato chloroplast. In fact, it modulates the day/night mRNA abundance of about 58% of the 114 ORFs. The effect of CRY2 includes a differential extension of some transcripts at their 5′‐end, according to the period of the day. We observed that the influence of CRY2 on chloroplast transcription is not limited to coding RNA; a great number of putative noncoding micro RNA also showed differential accumulation pattern. To our knowledge, this is the first study that highlights how a photoreceptor affects the day/night transcription of the chloroplast genome.

show abstract

Plant Sigma Factors

Cuitun‐Coronado¹,

Dodd²

2020

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Photosynthesis within chloroplasts is crucial for ecosystem function and all agricultural productivity. Chloroplasts are a type of plastid and contain a small circular genome of prokaryotic origin. This genome encodes proteins crucial for chloroplast function and requires correct regulation of gene expression. One cellular mechanism regulating plastid gene transcription involves sigma factors, which in plants are nuclear‐encoded proteins forming part of the chloroplast transcriptional system. These are required for chloroplast gene promoter recognition and transcription initiation, with specific sigma factors thought to recognise specific chloroplast promoters. Plant sigma factors participate in the adjustment of chloroplast transcription in response to environmental fluctuations and during development. They appear to be ancient, originating from photosynthetic bacteria that were chloroplast ancestors, with an increase in sigma factor copy number during plant evolution providing an example of the evolution of cell signalling. We examine the origins, structure, function and environmental signalling by plant sigma factors. Key Concepts Chloroplasts contain a small circular genome that encodes essential components of the photosynthetic apparatus and machinery for plastid transcription/translation. Some higher plant sigma factors participate in the integration of environmental signals that regulate chloroplast gene transcription. Sigma factors are found in bacteria to higher plants. In plants, they are important regulators of chloroplast transcription. Higher plant sigma factors allow the nuclear control of chloroplast transcription, forming a signalling pathway from the nucleus to chloroplasts. Higher plant sigma factors are thought to have evolved from sigma factors of photosynthetic bacteria that were engulfed by eukaryotic cells during the evolution of chloroplasts. During plant evolution, they transferred to the nuclear genome.

show abstract

Three new nuclear genes, sigD, sigE and sigF, encoding putative plastid RNA polymerase σ factors in Arabidopsis thaliana

Cited by 88 publications

References 32 publications

AtSig5 Is an Essential Nucleus-Encoded Arabidopsis σ-Like Factor

AtSig5 Is an Essential Nucleus-Encoded Arabidopsis σ-Like Factor

Cryptochrome 2 extensively regulates transcription of the chloroplast genome in tomato

Plant Sigma Factors

Contact Info

Product

Resources

About