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1.
Molecular characterization of a fourth isoform of the catalytic subunit of protein phosphatase 2A from Arabidopsis thaliana 总被引:1,自引:0,他引:1
Antonio Casamayor Encarna Pérez-Callejón Gemma Pujol Joaquín Ariño Albert Ferrer 《Plant molecular biology》1994,26(1):523-528
We have recently reported the existence of multiple isoforms of the catalytic subunit of protein phosphatase 2A (PP2A) in Arabidopsis thaliana and the molecular cloning of cDNAs encoding three of these proteins (PP2A-1, PP2A-2, PP2A-3). The reported cDNA encoding PP2A-3 was truncated at the 5 terminus, lacking a short fragment of the N-terminal coding sequence. We have now isolated a near full-length cDNA encoding the entire PP2A-3 protein (313 residues). The clone includes 188 nucleotides of 5-untranslated region, where a 44 bp long poly(GA) track is found. We also describe the cloning of a cDNA encoding a fourth isoform of PP2A (PP2A-4). The polypeptide contains 313 residues being 98% identical to PP2A-3 and only 80% identical to both PP2A-1 and PP2A-2. The mRNA for PP2A-4 is 1.4 kb in length and, although predominantly expressed in roots, it is also found in other organs. It is concluded that in A. thaliana the isoforms of PP2A can be grouped in two extremely conserved subfamilies. 相似文献
2.
Gemma Fabris M. Pilar Marco Francisco Camps 《Archives of insect biochemistry and physiology》1994,27(2):77-87
The control of Spodoptera littoralis sex pheromone biosynthesis has been investigated with synthetic pheromone biosynthesis activating neuropeptide (PBAN) and different labeled tracers using an in vitro isolated gland system. Responsiveness of the glands to PBAN stimulation was impaired by careless tissue manipulation. The fact that PBAN is active in the isolated gland system suggests that this might be a target organ for this peptide in S. littoralis. As reported previously with Br-SOG extracts and intact females, label incorporation into the pheromone increased in glands treated with PBAN from all the precursors tested. However, the formation of labeled intermediates from d5E11–14:Acid also occurred in glands incubated in the absence of the peptide, but the amounts of d5Z9, E11–14:Acid were lower in PBAN treated glands than in controls. These results indicate that PBAN controls pheromone biosynthesis in S. littoralis by regulating the reduction of acyl moieties. © 1994 Wiley-Liss, Inc. 相似文献
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Can Baysal Luisa Bortesi Changfu Zhu Gemma Farré Stefan Schillberg Paul Christou 《Molecular breeding : new strategies in plant improvement》2016,36(8):108
Genome editing with the CRISPR/Cas9 system allows mutations to be induced at any 20-bp target site in the genome preceded by the short protospacer adjacent motif (PAM) 5′-NGG-3′. The brevity and degeneracy of the PAM ensures that the motif occurs every ~10 bp in plant genomes, and all plant genes therefore contain many targetable sites. However, the CRISPR/Cas9 system tolerates up to three mismatches in the target site, so the ability to target genes in a specific manner requires the design of synthetic guide RNAs (sgRNAs) that do not bind off-target sites anywhere else in the genome. This is straightforward for single-copy genes but more challenging if a target gene has one or more paralogs because the principles that balance targeting efficiency (the frequency of on-target mutations) and accuracy (the absence of off-target mutations) are not fully understood and may be partially species-dependent. To investigate this phenomenon in rice, we targeted the rice starch branching enzyme IIb gene (OsBEIIb) with two sgRNAs designed to differ at two and six positions, respectively, from corresponding sites in the close paralog OsBEIIa. In each case, half of the mismatches were in the essential seed region immediately upstream of the PAM, where exact pairing is thought to be necessary, and the other half were in the distal part of the target. The sgRNAs also differed in predicted targeting efficiency (39 and 96 %, respectively). We found that the sgRNA with the low predicted efficiency was actually the most efficient in practice, achieving a mutation frequency of 5 % at the target site, whereas the sgRNA with the high predicted efficiency generated no mutations at the second target site. Furthermore, neither of the sgRNAs induced an off-target mutation in the OsBEIIa gene. Our data indicate that efficiency predictions should be tested empirically because they do not always reflect the experimental outcome and that a 1-bp mismatch in the seed region of a sgRNA is sufficient to avoid off-target effects even in closely related rice genes. 相似文献
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Enzymes are basically composed of 20 naturally occurring amino acids, yet they catalyse a dizzying array of chemical reactions, with regiospecificity and stereospecificity and under physiological conditions. In this review, we attempt to gain some understanding of these complex proteins, from the chemical versatility of the catalytic toolkit, including the use of cofactors (both metal ions and organic molecules), to the complex mapping of reactions to proteins (which is rarely one-to-one), and finally the structural complexity of enzymes and their active sites, often involving multidomain or multisubunit assemblies. This work highlights how the enzymes that we see today reflect millions of years of evolution, involving de novo design followed by exquisite regulation and modulation to create optimal fitness for life. 相似文献
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Gemma Aragonès Kalavathi Dasuri Opeoluwa Olukorede Sarah G. Francisco Carol Renneburg Caroline Kumsta Malene Hansen Shun Kageyama Masaaki Komatsu Sheldon Rowan Jonathan Volkin Michael Workman Wenxin Yang Paula Daza Diego Ruano Helena Dominguez‐Martín José Antonio Rodríguez‐Navarro Xue‐Liang Du Michael A. Brownlee Eloy Bejarano Allen Taylor 《Aging cell》2020,19(11)
9.
Blanca Domenech‐Ximenos Victor Cuba Pepus Daunis‐i‐Estadella Santiago Thi‐Henestrosa Francisco Jaldo Carles Biarnes Xavier Molina Gemma Xifra Wifredo Ricart Anton Bardera Imma Boada Marco Essig Salvador Pedraza Massimo Federici Jos Manuel Fernndez‐Real Josep Puig 《Obesity (Silver Spring, Md.)》2020,28(9):1663-1670
10.
John A. Shivik Gemma L. Palmer Eric M. Gese Britta Osthaus 《Journal of applied animal welfare science : JAAWS》2013,16(3):223-235
This article attempts to determine the effects of environment (captive or wild) and a simple form of environmental enrichment on the behavior and physiology of a nonhuman animal. Specifically, analyses first compared behavioral budgets and stereotypic behavior of captive coyotes (Canis latrans) in kennels and pens to their counterparts in the wild. Second, experiments examined the effect of a simple form of environmental enrichment for captive coyotes (food-filled bones) on behavioral budgets, stereotypies, and corticosteroid levels. Overall, behavioral budgets of captive coyotes in both kennels and pens were similar to those observed in the wild, but coyotes in captivity exhibited significantly more stereotypic behavior. Intermittently providing a bone generally lowered resting and increased foraging behaviors but did not significantly reduce stereotypic behavior or alter corticosteroid levels. Thus, coyote behavior in captivity can be similar to that exhibited in the wild; in addition, although enrichment can affect proportions of elicited behaviors, abnormal behaviors and corticosteroid levels may require more than a simple form of environmental enrichment for their reduction. 相似文献