Identification and developmental regulation of a neuron-specific subunit of cytoplasmic dynein.

Cytoplasmic dynein is the microtubule minus-end-directed motor for the retrograde axonal transport of membranous organelles. Because of its similarity to the intermediate chains of flagellar dynein, the 74-kDa intermediate chain (IC74) subunit of dynein is thought to be involved in binding dynein to its membranous organelle cargo. Previously, we identified six isoforms of the IC74 cytoplasmic dynein subunit in the brain. We further demonstrated that cultured glia and neurons expressed different dynein IC74 isoforms and phospho-isoforms. Two isoforms were observed when dynein from glia was analyzed. When dynein from cultured neurons was analyzed, six IC74 isoforms were observed, although the relative amounts of the dynein isoforms from cultured neurons differed from those found in dynein from brain. To better understand the role of the neuronal IC74 isoforms and identify neuron-specific IC74 dynein subunits, the expression of the IC74 protein isoforms and mRNAs of various tissues were compared. As a result of this comparison, the identity of each of the isoform spots observed on two-dimensional gels was correlated with the products of each of the IC74 mRNAs. We also found that between the fifteenth day of gestation (E15) and the fifth day after birth (P5), the relative expression of the IC74 protein isoforms changes, demonstrating that the expression of IC74 isoforms is developmentally regulated in brain. During this time period, there is relatively little change in the abundance of the various IC74 mRNAs. The E15 to P5 time period is one of rapid process extension and initial pattern formation in the rat brain. This result indicates that the changes in neuronal IC74 isoforms coincide with neuronal differentiation, in particular the extension of processes. This suggests a role for the neuronal IC74 isoforms in the establishment or regulation of retrograde axonal transport.

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Functional interaction between dynein light chain and intermediate chain is required for mitotic spindle positioning

Molecular Biology of the Cell ◽

10.1091/mbc.e11-01-0075 ◽

2011 ◽

Vol 22 (15) ◽

pp. 2690-2701 ◽

Cited By ~ 23

Author(s):

Melissa D. Stuchell-Brereton ◽

Amanda Siglin ◽

Jun Li ◽

Jeffrey K. Moore ◽

Shubbir Ahmed ◽

...

Keyword(s):

Light Chain ◽

Direct Evidence ◽

Retrograde Transport ◽

Cytoplasmic Dynein ◽

Dynein Light Chain ◽

Spindle Positioning ◽

Dynein Motor ◽

Intermediate Chains ◽

Activator Complex

Cytoplasmic dynein is a large multisubunit complex involved in retrograde transport and the positioning of various organelles. Dynein light chain (LC) subunits are conserved across species; however, the molecular contribution of LCs to dynein function remains controversial. One model suggests that LCs act as cargo-binding scaffolds. Alternatively, LCs are proposed to stabilize the intermediate chains (ICs) of the dynein complex. To examine the role of LCs in dynein function, we used Saccharomyces cerevisiae, in which the sole function of dynein is to position the spindle during mitosis. We report that the LC8 homologue, Dyn2, localizes with the dynein complex at microtubule ends and interacts directly with the yeast IC, Pac11. We identify two Dyn2-binding sites in Pac11 that exert differential effects on Dyn2-binding and dynein function. Mutations disrupting Dyn2 elicit a partial loss-of-dynein phenotype and impair the recruitment of the dynein activator complex, dynactin. Together these results indicate that the dynein-based function of Dyn2 is via its interaction with the dynein IC and that this interaction is important for the interaction of dynein and dynactin. In addition, these data provide the first direct evidence that LC occupancy in the dynein motor complex is important for function.

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Developmental regulation of the mRNAs for elastins a, b and c in foetal-calf nuchal ligament and aorta

Biochemical Journal ◽

10.1042/bj2610227 ◽

1989 ◽

Vol 261 (1) ◽

pp. 227-232 ◽

Cited By ~ 3

Author(s):

R P Paulovic ◽

R A Anwar

Keyword(s):

Developmental Regulation ◽

Developmentally Regulated ◽

Foetal Development ◽

Tissue Specific ◽

Nuchal Ligament ◽

Self Aggregation

The data presented clearly suggest that relative amounts of mRNAs for elastins a, b and c are developmentally regulated in foetal-calf nuchal ligament and aorta and that this regulation is tissue-specific. In nuchal ligament, at earlier stages of foetal development, the relative amounts of mRNAs for elastins a and b are very low. After the foetal age of about 6 months the relative amount of mRNA for elastin b begins to increase. This is followed by an increase in the relative amount of mRNA for elastin a. In aorta, with increasing foetal age, the relative amounts of mRNAs for elastins b and c increase and decrease alternately. The relative amounts of mRNA for elastin a remain low, with only marginal increases with foetal age. A possible self-aggregation role of elastin a in elastogenesis is proposed.

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

Genetics ◽

10.1093/genetics/159.2.599 ◽

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.

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Role of cytoplasmic dynein in the axonal transport of microtubules and neurofilaments

The Journal of Cell Biology ◽

10.1083/jcb.200407191 ◽

2005 ◽

Vol 168 (5) ◽

pp. 697-703 ◽

Cited By ~ 153

Author(s):

Yan He ◽

Franto Francis ◽

Kenneth A. Myers ◽

Wenqian Yu ◽

Mark M. Black ◽

...

Keyword(s):

Rna Interference ◽

Axonal Transport ◽

Heavy Chain ◽

Live Cell Imaging ◽

Cell Imaging ◽

Sympathetic Neurons ◽

Cytoplasmic Dynein ◽

Live Cell ◽

Cytoskeletal Elements

Recent studies have shown that the transport of microtubules (MTs) and neurofilaments (NFs) within the axon is rapid, infrequent, asynchronous, and bidirectional. Here, we used RNA interference to investigate the role of cytoplasmic dynein in powering these transport events. To reveal transport of MTs and NFs, we expressed EGFP-tagged tubulin or NF proteins in cultured rat sympathetic neurons and performed live-cell imaging of the fluorescent cytoskeletal elements in photobleached regions of the axon. The occurrence of anterograde MT and retrograde NF movements was significantly diminished in neurons that had been depleted of dynein heavy chain, whereas the occurrence of retrograde MT and anterograde NF movements was unaffected. These results support a cargo model for NF transport and a sliding filament model for MT transport.

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Role of gangliosides in the uptake and retrograde axonal transport of cholera and tetanus toxin as compared to nerve growth factor and wheat germ agglutinin

Brain Research ◽

10.1016/0006-8993(77)90421-8 ◽

1977 ◽

Vol 132 (2) ◽

pp. 273-285 ◽

Cited By ~ 133

Author(s):

K. Stoeckel ◽

M. Schwab ◽

H. Thoenen

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Axonal Transport ◽

Tetanus Toxin ◽

Wheat Germ Agglutinin ◽

Wheat Germ ◽

Retrograde Axonal Transport ◽

Nerve Growth

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Faculty Opinions recommendation of Trk activation of the ERK1/2 kinase pathway stimulates intermediate chain phosphorylation and recruits cytoplasmic dynein to signaling endosomes for retrograde axonal transport.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717962627.793464622 ◽

2012 ◽

Author(s):

Scott T Brady

Keyword(s):

Axonal Transport ◽

Cytoplasmic Dynein ◽

Retrograde Axonal Transport ◽

Kinase Pathway ◽

Intermediate Chain

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Evolutionary conservation of the structure and expression of alternatively spliced Ultrabithorax isoforms from Drosophila.

Genetics ◽

10.1093/genetics/136.3.965 ◽

1994 ◽

Vol 136 (3) ◽

pp. 965-977

Author(s):

H M Bomze ◽

A J López

Keyword(s):

Alternative Splicing ◽

Protein Function ◽

Developmental Regulation ◽

Expression Patterns ◽

Proximal Region ◽

Amino Acid Sequences ◽

Drosophila Virilis ◽

Protein Isoforms ◽

Developmentally Regulated ◽

Alternatively Spliced

Abstract In Drosophila melanogaster, alternatively spliced mRNAs from the homeotic gene Ultrabithorax (Ubx) encode a family of structurally distinct homeoprotein isoforms. The developmentally regulated expression patterns of these isoforms suggest that they have specialized stage- and tissue-specific functions. To evaluate the functional importance of UBX isoform diversity and gain clues to the mechanism that regulates processing of Ubx RNAs, we have investigated whether the Ubx RNAs of other insects undergo similar alternative splicing. We have isolated and characterized Ubx cDNA fragments from D. melanogaster, Drosophila pseudoobscura, Drosophila hydei and Drosophila virilis, species separated by as much as 60 million years of evolution, and have found that three aspects of Ubx RNA processing have been conserved. (1) These four species exhibit identical patterns of optional exon use in a region adjacent to the homeodomain. (2) These four species produce the same family of UBX protein isoforms with identical amino acid sequences in the optional exons, even though the common amino-proximal region has undergone substantial divergence. The nucleotide sequences of the optional exons, including third positions of rare codons, have also been conserved strongly, suggesting functional constraints that are not limited to coding potential. (3) The tissue- and stage-specific patterns of expression of different UBX isoforms are identical among these Drosophila species, indicating that the developmental regulation of the alternative splicing events has also been conserved. These findings argue for an important role of alternative splicing in Ubx function. We discuss the implications of these results for models of UBX protein function and the mechanism of alternative splicing.

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A Conserved Role for Vezatin Proteins in Cargo-Specific Regulation of Retrograde Axonal Transport

Genetics ◽

10.1534/genetics.120.303499 ◽

2020 ◽

Vol 216 (2) ◽

pp. 431-445 ◽

Cited By ~ 1

Author(s):

Michael A. Spinner ◽

Katherine Pinter ◽

Catherine M. Drerup ◽

Tory G. Herman

Keyword(s):

Axonal Transport ◽

Retrograde Transport ◽

Cytoplasmic Dynein ◽

Retrograde Axonal Transport ◽

Cell Junctions ◽

Loss Of Function ◽

Axon Terminals ◽

Bmp Receptors ◽

New Material ◽

Specific Regulation

Active transport of organelles within axons is critical for neuronal health. Retrograde axonal transport, in particular, relays neurotrophic signals received by axon terminals to the nucleus and circulates new material among en passant synapses. A single motor protein complex, cytoplasmic dynein, is responsible for nearly all retrograde transport within axons: its linkage to and transport of diverse cargos is achieved by cargo-specific regulators. Here, we identify Vezatin as a conserved regulator of retrograde axonal transport. Vertebrate Vezatin (Vezt) is required for the maturation and maintenance of cell-cell junctions and has not previously been implicated in axonal transport. However, a related fungal protein, VezA, has been shown to regulate retrograde transport of endosomes in hyphae. In a forward genetic screen, we identified a loss-of-function mutation in the Drosophila vezatin-like (vezl) gene. We here show that vezl loss prevents a subset of endosomes, including signaling endosomes containing activated BMP receptors, from initiating transport out of motor neuron terminal boutons. vezl loss also decreases the transport of endosomes and dense core vesicles, but not mitochondria, within axon shafts. We disrupted vezt in zebrafish and found that vezt loss specifically impairs the retrograde axonal transport of late endosomes, causing their accumulation in axon terminals. Our work establishes a conserved, cargo-specific role for Vezatin proteins in retrograde axonal transport.

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