Characterization of the cis-acting element directing perinuclear localization of the metallothionein-1 mRNA

2004 ◽  
Vol 32 (5) ◽  
pp. 702-704 ◽  
Author(s):  
H. Chabanon ◽  
D. Nury ◽  
I. Mickleburgh ◽  
B. Burtle ◽  
J. Hesketh
Keyword(s):  
Structural Features ◽  
Transfected Cells ◽  
Cis Acting ◽  
Cis Element ◽  
Chemical Probing ◽  
Perinuclear Cytoplasm ◽  
Localization Signal ◽  
Localization Element ◽  
Mrna Targeting

Subcellular localization of mRNAs is a key mechanism for the synthesis of proteins close to their site of function. The mRNA encoding MT-1 (metallothionein-1) is localized in the perinuclear cytoplasm, where it is associated with cytoskeletal-bound polysomes. This localization relies on sequences present in the 3′-UTR (3′-untranslated region). The present study aims to characterize the cis-acting localization element(s) within the 3′-UTR. Using transfected cells expressing tagged MT-1 differing in their 3′-UTRs (deleted or mutated), the section(s) of this region required for directing MT-1 transcripts to the perinuclear cytoplasm has been investigated. Different 3′-UTRs were also used in UV cross-linking experiments that highlighted two distinct regions (nt 26–30 and 66–76) necessary for the binding of a protein of approx. 50 kDa, presumably involved in the mRNA targeting. The poor sequence homology between the MT-1 3′-UTR of various species, together with the bipartite nature of the required cis-element, indicates the involvement of a particular structure in the localization signal. The secondary structure of the MT-1 3′-UTR was investigated using enzymic and chemical probing. Current structural analysis of mutant 3′-UTRs will allow the critical structural features of the MT-1 mRNA perinuclear localization signal to be defined.

scholarly journals Characterization of cis-acting element in renal NaPi-2 cotransporter mRNA that determines mRNA stability

2003 ◽  
Vol 284 (4) ◽  
pp. F663-F670 ◽  
Author(s):  
Yulia Moz ◽  
Justin Silver ◽  
Tally Naveh-Many
Keyword(s):  
Fluorescent Protein ◽  
Mrna Levels ◽  
In Vitro Degradation ◽  
Cis Acting ◽  
Cis Element ◽  
Protein Binding Region ◽  
Green Fluorescent ◽  
Subsequent Stabilization

Hypophosphatemia leads to an increase in Na+-Pi cotransporter (NaPi-2) mRNA levels. This increase is posttranscriptional and correlates with a more stable transcript mediated by the terminal 698 nt of the NaPi-2 mRNA. A 71-nt binding element was identified with renal proteins from rats fed control and low-Pi (−Pi) diet. The binding of −Pi renal proteins to this transcript was increased compared with control proteins. The functionality of the ciselement was demonstrated by an in vitro degradation assay. −Pi renal proteins stabilized transcripts that included the cis element compared with control renal extracts. The full-length NaPi-2 transcript, but not control transcripts, was stabilized by −Pi extracts. Insertion of the binding element into green fluorescent protein (GFP) as a reporter gene decreased chimeric GFP mRNA levels in transfection experiments. Our results suggest that the protein-binding region of the NaPi-2 mRNA functions as a cis-acting instability element. In hypophosphatemia there is increased binding to the cis-acting element and subsequent stabilization of NaPi-2 mRNA.

Two copies of a subelement from the Vg1 RNA localization sequence are sufficient to direct vegetal localization in Xenopus oocytes

Development ◽  
1997 ◽  
Vol 124 (24) ◽  
pp. 5013-5020 ◽  
Author(s):  
D. Gautreau ◽  
C.A. Cote ◽  
K.L. Mowry
Keyword(s):  
Xenopus Oocytes ◽  
Rna Localization ◽  
Sequence Motifs ◽  
Sequence Element ◽  
Cis Acting ◽  
Vegetal Cortex ◽  
Sequence Elements ◽  
Localization Sequence ◽  
Localization Signal ◽  
Localization Element

Localization of mRNA has emerged as a fundamental mechanism for generating polarity during development. In vertebrates, one example of this phenomenon is Vg1 RNA, which is localized to the vegetal cortex of Xenopus oocytes. Vegetal localization of Vg1 RNA is directed by a 340-nt sequence element contained within its 3′ untranslated region. To investigate how such cis-acting elements function in the localization process, we have undertaken a detailed analysis of the precise sequence requirements for vegetal localization within the 340-nt localization element. We present evidence for considerable redundancy within the localization element and demonstrate that critical sequences lie at the ends of the element. Importantly, we show that a subelement from the 5′ end of the Vg1 localization element is, when duplicated, sufficient to direct vegetal localization. We suggest that the Vg1 localization element is composed of smaller, redundant sequence motifs and identify one such 6-nt motif as essential for localization. These results allow insight into what constitutes an RNA localization signal and how RNA sequence elements may act in the localization process.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Ultrastructural identification of three types of sensory setae on copepod antennae

1995 ◽  
Vol 53 ◽  
pp. 956-957
Author(s):  
T. M. Weatherby ◽  
P.H. Lenz
Keyword(s):  
Phase Locking ◽  
Membrane Surface ◽  
Reaction Times ◽  
High Sensitivity ◽  
Structural Features ◽  
Calanoid Copepods ◽  
Marine Food Webs ◽  
Dendritic Membrane ◽  
Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

kangaroo, a Mobile Element From Volvox carteri, Is a Member of a Newly Recognized Third Class of Retrotransposons

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1617-1630
Author(s):  
Leonard Duncan ◽  
Kristine Bouckaert ◽  
Fay Yeh ◽  
David L Kirk
Keyword(s):  
Genomic Structure ◽  
Mobile Element ◽  
Direct Repeat ◽  
Structural Features ◽  
Volvox Carteri ◽  
Developmentally Regulated ◽  
Closed Circle ◽  
Integration Mechanisms ◽  
And Function

Abstract Retrotransposons play an important role in the evolution of genomic structure and function. Here we report on the characterization of a novel retrotransposon called kangaroo from the multicellular green alga, Volvox carteri. kangaroo elements are highly mobile and their expression is developmentally regulated. They probably integrate via double-stranded, closed-circle DNA intermediates through the action of an encoded recombinase related to the λ-site-specific integrase. Phylogenetic analysis indicates that kangaroo elements are closely related to other unorthodox retrotransposons including PAT (from a nematode), DIRS-1 (from Dictyostelium), and DrDIRS1 (from zebrafish). PAT and kangaroo both contain split direct repeat (SDR) termini, and here we show that DIRS-1 and DrDIRS1 elements contain terminal features structurally related to SDRs. Thus, these mobile elements appear to define a third class of retrotransposons (the DIRS1 group) that are unified by common structural features, genes, and integration mechanisms, all of which differ from those of LTR and conventional non-LTR retrotransposons.

scholarly journals Identification and Characterization of Abiotic Stress Responsive CBL-CIPK Family Genes in Medicago

2021 ◽  
Vol 22 (9) ◽  
pp. 4634
Author(s):  
Wenxuan Du ◽  
Junfeng Yang ◽  
Lin Ma ◽  
Qian Su ◽  
Yongzhen Pang
Keyword(s):  
Abiotic Stress ◽  
Abiotic Stresses ◽  
Expression Patterns ◽  
Interacting Protein ◽  
Forage Crop ◽  
Cis Acting ◽  
Protein Motifs ◽  
Plant Signal Transduction ◽  
Identification And Characterization

The calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) play important roles in plant signal transduction and response to abiotic stress. Plants of Medicago genus contain many important forages, and their growth is often affected by a variety of abiotic stresses. However, studies on the CBL and CIPK family member and their function are rare in Medicago. In this study, a total of 23 CBL and 58 CIPK genes were identified from the genome of Medicago sativa as an important forage crop, and Medicaog truncatula as the model plant. Phylogenetic analysis suggested that these CBL and CIPK genes could be classified into five and seven groups, respectively. Moreover, these genes/proteins showed diverse exon-intron organizations, architectures of conserved protein motifs. Many stress-related cis-acting elements were found in their promoter region. In addition, transcriptional analyses showed that these CBL and CIPK genes exhibited distinct expression patterns in various tissues, and in response to drought, salt, and abscisic acid treatments. In particular, the expression levels of MtCIPK2 (MsCIPK3), MtCIPK17 (MsCIPK11), and MtCIPK18 (MsCIPK12) were significantly increased under PEG, NaCl, and ABA treatments. Collectively, our study suggested that CBL and CIPK genes play crucial roles in response to various abiotic stresses in Medicago.

Characterization of putative salinity-responsive biomarkers in olive (Olea europaea L.)

2021 ◽  
pp. 1-11
Author(s):  
Monther T. Sadder ◽  
Ahmad F. Ateyyeh ◽  
Hodayfah Alswalmah ◽  
Adel M. Zakri ◽  
Abdullah A. Alsadon ◽  
...  
Keyword(s):  
Food Production ◽  
Stress Protein ◽  
Adaptor Protein ◽  
Structural Features ◽  
Nacl Stress ◽  
Soil Salinization ◽  
Limiting Factors ◽  
Stress Levels ◽  
Quality Water

Abstract Low-quality water and soil salinization are increasingly becoming limiting factors for food production, including olive – a major fruit crop in several parts of the world. Identifying putative salinity-stress tolerance in olive would be helpful in the future development of new tolerant varieties. In this study, novel salinity-responsive biomarkers (SRBs) were characterized in the species, namely, monooxygenase 1 (OeMO1), cation calcium exchanger 1 (OeCCX1), salt tolerance protein (OeSTO), proteolipid membrane potential modulator (OePMP3), universal stress protein (OeUSP2), adaptor protein complex 4 medium mu4 subunit (OeAP-4), WRKY1 transcription factor (OeWRKY1) and potassium transporter 2 (OeKT2). Unique structural features were highlighted for encoded proteins as compared with other plant homologues. The expression of olive SRBs was investigated in leaves of young plantlets of two cultivars, ‘Nabali’ (moderately tolerant) and ‘Picual’ (tolerant). At 60 mM NaCl stress level, OeMO1, OeSTO, OePMP3, OeUSP2, OeAP-4 and OeWRKY1 were up-regulated in ‘Nabali’ as compared with ‘Picual’. On the other hand, OeCCX1 and OeKT2 were up-regulated at three stress levels (30, 60 and 90 mM NaCl) in ‘Picual’ as compared to ‘Nabali’. Salinity tolerance in olive presumably engages multiple sets of responsive genes triggered by different stress levels.

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