scholarly journals Juvenile and mature MAP2 isoforms induce distinct patterns of process outgrowth.

1996 ◽  
Vol 7 (3) ◽  
pp. 443-455 ◽  
Author(s):  
N Leclerc ◽  
P W Baas ◽  
C C Garner ◽  
K S Kosik
Keyword(s):  
Alternative Splicing ◽  
Spodoptera Frugiperda ◽  
Morphological Features ◽  
Developmentally Regulated ◽  
Architectural Elements ◽  
Molecular Masses ◽  
Process Outgrowth ◽  
Cell Expression

Microtubule-associated protein-2 (MAP2) is the most abundant MAP in neurons, where its distribution is restricted to the somatodendritic compartment. This molecule undergoes developmentally regulated alternative splicing, resulting in at least two isoforms, a juvenile isoform (termed MAP2c) and a mature isoform (MAP2), with greatly different molecular masses. Spodoptera frugiperda (Sf9) cell expression of the juvenile versus the mature MAP2 isoform generates two distinct patterns of process outgrowth. The smaller juvenile isoform induces multiple short thin processes. Mature MAP2 tends to induce single processes that are considerably thicker than those processes induced by juvenile MAP2. We found important differences in the variability of spacing between microtubules and the number of microtubules along the processes induced by MAP2c and mature MAP2. MAP2c showed variability with most microtubules spaced as closely as with tau, but some spaced as far apart as with mature MAP2. Over their length, the mature MAP2 processes demonstrate proximo-distal taper, which corresponds to a narrowing of the spacing between microtubules from 90 nm to 40 nm. Moreover, there is a decreased number of microtubules in mature MAP2-induced processes whereas in tau and MAP2-induced processes, the number of microtubules is constant along the length. Based on these observations, we conclude that MAP2 isoforms can serve as architectural elements by establishing specific morphological features of processes and specific arrangements of their microtubules.

scholarly journals Developmentally regulated expression, alternative splicing and distinct sub-groupings in members of the Schistosoma mansoni venom allergen-like (SmVAL) gene family

BMC Genomics ◽  
2008 ◽  
Vol 9 (1) ◽  
pp. 89 ◽  
Author(s):  
Iain W Chalmers ◽  
Andrew J McArdle ◽  
Richard MR Coulson ◽  
Marissa A Wagner ◽  
Ralf Schmid ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Schistosoma Mansoni ◽  
Gene Family ◽  
Developmentally Regulated ◽  
Regulated Expression ◽  
Venom Allergen

Expression of Winged Bean Basic Agglutinin in Spodoptera frugiperda Insect Cell Expression System

2001 ◽  
Vol 21 (3) ◽  
pp. 361-367 ◽  
Author(s):  
V. R. Srinivas ◽  
Kiran Bachhawat-Sikder ◽  
Saman Habib ◽  
Seyed E. Hasnain ◽  
Avadhesha Surolia
Keyword(s):  
Spodoptera Frugiperda ◽  
Expression System ◽  
Recombinant Baculovirus ◽  
Winged Bean ◽  
Carbohydrate Binding ◽  
Binding Properties ◽  
Insect Cell Expression System ◽  
Cell Expression ◽  
Insect Cell Expression ◽  
Cell Expression System

In this paper we report the successful expression of the winged bean basic agglutinin (WBA I) in insect cells infected with a recombinant baculovirus carrying the WBA I gene and its characterization in terms of its carbohydrate binding properties. The expressed protein appears to have a lower molecular weight than the native counterpart which is consistent with the lack of glycosylation of the former. Moreover, the expressed protein maintains its dimeric nature. Hence, a role for glycosylation in modulation of dimerization of WBA I is ruled out unlike Erythrina corallodendron (EcorL). Despite this the protein is active, with its sugar specificity unaltered.

scholarly journals Developmentally Regulated Alternative Splicing in a Novel Synaptojanin

1998 ◽  
Vol 273 (4) ◽  
pp. 2306-2311 ◽  
Author(s):  
Mikhail Khvotchev ◽  
Thomas C. Südhof
Keyword(s):  
Alternative Splicing ◽  
Developmentally Regulated

scholarly journals The CELF Family of RNA Binding Proteins Is Implicated in Cell-Specific and Developmentally Regulated Alternative Splicing

2001 ◽  
Vol 21 (4) ◽  
pp. 1285-1296 ◽  
Author(s):  
Andrea N. Ladd ◽  
Nicolas Charlet-B. ◽  
Thomas A. Cooper
Keyword(s):  
Alternative Splicing ◽  
Heart Development ◽  
Binding Proteins ◽  
Rna Binding ◽  
Striated Muscle ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Protein Isoforms ◽  
Developmentally Regulated ◽  
Exon Inclusion

ABSTRACT Alternative splicing of cardiac troponin T (cTNT) exon 5 undergoes a developmentally regulated switch such that exon inclusion predominates in embryonic, but not adult, striated muscle. We previously described four muscle-specific splicing enhancers (MSEs) within introns flanking exon 5 in chicken cTNT that are both necessary and sufficient for exon inclusion in embryonic muscle. We also demonstrated that CUG-binding protein (CUG-BP) binds a conserved CUG motif within a human cTNT MSE and positively regulates MSE-dependent exon inclusion. Here we report that CUG-BP is one of a novel family of developmentally regulated RNA binding proteins that includes embryonically lethal abnormal vision-type RNA binding protein 3 (ETR-3). This family, which we call CELF proteins for CUG-BP- and ETR-3-like factors, specifically bound MSE-containing RNAs in vitro and activated MSE-dependent exon inclusion of cTNT minigenes in vivo. The expression of two CELF proteins is highly restricted to brain. CUG-BP, ETR-3, and CELF4 are more broadly expressed, and expression is developmentally regulated in striated muscle and brain. Changes in the level of expression and isoforms of ETR-3 in two different developmental systems correlated with regulated changes in cTNT splicing. A switch from cTNT exon skipping to inclusion tightly correlated with induction of ETR-3 protein expression during differentiation of C2C12 myoblasts. During heart development, the switch in cTNT splicing correlated with a transition in ETR-3 protein isoforms. We propose that ETR-3 is a major regulator of cTNT alternative splicing and that the CELF family plays an important regulatory role in cell-specific alternative splicing during normal development and disease.

scholarly journals Alternative Splicing of the Drosophila Dscam Pre-mRNA Is Both Temporally and Spatially Regulated

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 599-608
Author(s):  
Alicia M Celotto ◽  
Brenton R Graveley
Keyword(s):  
Alternative Splicing ◽  
Axon Guidance ◽  
Neural Development ◽  
Cell Adhesion Molecule ◽  
Developmental Regulation ◽  
Mrna Isoforms ◽  
Developmentally Regulated ◽  
Early Embryos ◽  
Exon 4

Abstract The Drosophila melanogaster Down syndrome cell adhesion molecule (Dscam) gene encodes an axon guidance receptor that can express 38,016 different mRNAs by virtue of alternative splicing. The Dscam gene contains 95 alternative exons that are organized into four clusters of 12, 48, 33, and 2 exons each. Although numerous Dscam mRNA isoforms can be synthesized, it remains to be determined whether different Dscam isoforms are synthesized at different times in development or in different tissues. We have investigated the alternative splicing of the Dscam exon 4 cluster, which contains 12 mutually exclusive alternative exons, and found that Dscam exon 4 alternative splicing is developmentally regulated. The most highly regulated exon, 4.2, is infrequently used in early embryos but is the predominant exon 4 variant used in adults. Moreover, the developmental regulation of exon 4.2 alternative splicing is conserved in D. yakuba. In addition, different adult tissues express distinct collections of Dscam mRNA isoforms. Given the role of Dscam in neural development, these results suggest that the regulation of alternative splicing plays an important role in determining the specificity of neuronal wiring. In addition, this work provides a framework to determine the mechanisms by which complex alternative splicing events are regulated.

scholarly journals Calcium current modulation by the γ1 subunit depends on alternative splicing of CaV1.1

2021 ◽  
Author(s):  
Yousra El El Ghaleb ◽  
Nadine J. Ortner ◽  
Wilfried Posch ◽  
Monica L. Fernandez-Quintero ◽  
Wietske E. Tuinte ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Current Density ◽  
Voltage Dependence ◽  
Splice Variants ◽  
Calcium Currents ◽  
Developmentally Regulated ◽  
The Difference ◽  
Ion Conducting ◽  
And Shifts ◽  
Oppositely Charged

The skeletal muscle voltage-gated calcium channel (CaV1.1) primarily functions as voltage sensor for excitation-contraction coupling. Conversely, its ion-conducting function is modulated by multiple mechanisms within the pore-forming α1S subunit and the auxiliary α2δ-1 and γ1 subunits. Particularly, developmentally regulated alternative splicing of exon 29, which inserts 19 amino acids in the extracellular IVS3-S4 loop of CaV1.1a, greatly reduces the current density and shifts the voltage-dependence of activation to positive potentials outside the physiological range. We generated a new HEK293-cell line stably expressing α2δ-1, β3, and STAC3. When the adult (CaV1.1a) and the embryonic (CaV1.1e) splice variants were expressed in these cells, the difference in the voltage-dependence of activation observed in muscle cells was reproduced, but not the reduced current density of CaV1.1a. Only when we further co-expressed the γ1 subunit, the current density of CaV1.1a, but not of CaV1.1e, was reduced by >50 %. In addition, γ1 caused a shift of the voltage-dependence of inactivation to negative voltages in both variants. Thus, the current-reducing effect of γ1, but not its effect on inactivation, is specifically dependent on the inclusion of exon 29 in CaV1.1a. Molecular structure modeling revealed several direct ionic interactions between oppositely charged residues in the IVS3-S4 loop and the γ1 subunit. However, substitution of these residues by alanine, individually or in combination, did not abolish the γ1-dependent reduction of current density, suggesting that structural rearrangements of CaV1.1a induced by inclusion of exon 29 allosterically empower the γ1 subunit to exert its inhibitory action on CaV1.1 calcium currents.

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