scholarly journals ROLE FOR NETRIN-1 IN SENSORY AXONAL GUIDANCE IN HIGHER VERTEBRATES

2009 ◽  
Vol 55 (1) ◽  
pp. 1-6 ◽  
Author(s):  
TOMOYUKI MASUDA ◽  
CHIE SAKUMA ◽  
HIROYUKI YAGINUMA
Keyword(s):  
Axonal Guidance

scholarly journals Glycosylation in Axonal Guidance

2021 ◽  
Vol 22 (10) ◽  
pp. 5143
Author(s):  
Sampada P. Mutalik ◽  
Stephanie L. Gupton
Keyword(s):  
Neuronal Development ◽  
Axonal Guidance ◽  
Axonal Outgrowth ◽  
Axonal Pathfinding ◽  
Guidance Cues ◽  
Functional Implications ◽  
Protein Functions ◽  
Guidance Receptors ◽  
Surface Localization

How millions of axons navigate accurately toward synaptic targets during development is a long-standing question. Over decades, multiple studies have enriched our understanding of axonal pathfinding with discoveries of guidance molecules and morphogens, their receptors, and downstream signalling mechanisms. Interestingly, classification of attractive and repulsive cues can be fluid, as single guidance cues can act as both. Similarly, guidance cues can be secreted, chemotactic cues or anchored, adhesive cues. How a limited set of guidance cues generate the diversity of axonal guidance responses is not completely understood. Differential expression and surface localization of receptors, as well as crosstalk and spatiotemporal patterning of guidance cues, are extensively studied mechanisms that diversify axon guidance pathways. Posttranslational modification is a common, yet understudied mechanism of diversifying protein functions. Many proteins in axonal guidance pathways are glycoproteins and how glycosylation modulates their function to regulate axonal motility and guidance is an emerging field. In this review, we discuss major classes of glycosylation and their functions in axonal pathfinding. The glycosylation of guidance cues and guidance receptors and their functional implications in axonal outgrowth and pathfinding are discussed. New insights into current challenges and future perspectives of glycosylation pathways in neuronal development are discussed.

Tissue-engineering approaches for axonal guidance

2005 ◽  
Vol 49 (1) ◽  
pp. 48-64 ◽  
Author(s):  
Ning Zhang ◽  
Honghai Yan ◽  
Xuejun Wen
Keyword(s):  
Tissue Engineering ◽  
Axonal Guidance

Caenorhabditis elegansPlexinA, PLX-1, interacts with transmembrane semaphorins and regulates epidermal morphogenesis

Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2053-2063 ◽  
Author(s):  
Takashi Fujii ◽  
Fumi Nakao ◽  
Yukimasa Shibata ◽  
Go Shioi ◽  
Eiji Kodama ◽  
...  
Keyword(s):  
Rna Interference ◽  
Morphological Changes ◽  
Expression System ◽  
Transmembrane Proteins ◽  
Axonal Guidance ◽  
Heterologous Expression System ◽  
C Elegans ◽  
Morphological Defects ◽  
Epidermal Morphogenesis ◽  
Null Mutants

The plexin family transmembrane proteins are putative receptors for semaphorins, which are implicated in the morphogenesis of animal embryos, including axonal guidance. We have generated and characterized putative null mutants of the C. elegans plexinA gene, plx-1. plx-1 mutants exhibited morphological defects: displacement of ray 1 and discontinuous alae. The epidermal precursors for the affected organs were aberrantly arranged in the mutants, and a plx-1::gfp transgene was expressed in these epidermal precursor cells as they underwent dynamic morphological changes. Suppression of C. elegans transmembrane semaphorins, Ce-Sema-1a and Ce-Sema-1b, by RNA interference caused a displacement of ray 1 similar to that of plx-1 mutants, whereas mutants for the Ce-Sema-2a/mab-20 gene, which encodes a secreted-type semaphorin, exhibited phenotypes distinct from those of plx-1 mutants. A heterologous expression system showed that Ce-Sema-1a, but not Ce-Sema-2a, physically bound to PLX-1. Our results indicate that PLX-1 functions as a receptor for transmembrane-type semaphorins, and, though Ce-Sema-2a and PLX-1 both play roles in the regulation of cellular morphology during epidermal morphogenesis, they function rather independently.

scholarly journals Comprehensive analysis of neuronal guidance cue expression regulation during monocyte-to-macrophage differentiation reveals post-transcriptional regulation of semaphorin7A by the RNA-binding protein quaking

2020 ◽  
pp. 175342592096664
Author(s):  
Huayu Zhang ◽  
Jurriën Prins ◽  
Dianne Vreeken ◽  
Barend W Florijn ◽  
Ruben G de Bruin ◽  
...  
Keyword(s):  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Comprehensive Analysis ◽  
Expression Regulation ◽  
Axonal Guidance ◽  
Macrophage Differentiation ◽  
Monocyte Differentiation ◽  
Guidance Cue ◽  
Neuronal Guidance

In response to inflammatory cytokines and chemokines, monocytes differentiate into macrophages. Comprehensive analysis of gene expression regulation of neuronal guidance cue (NGC) ligands and receptors in the monocyte-to-macrophage differentiation process is not available yet. We performed transcriptome profiling in both human primary PBMCs/PBMC-derived macrophages and THP-1 cells/THP-1-macrophages using microarray or RNA sequencing methods. Pathway analysis showed that the axonal guidance pathway is significantly regulated upon monocyte differentiation. We confirmed NGC ligands and receptors which were consistently regulated, including SEMA4D, SEMA7A, NRP1, NRP2, PLXNA1 and PLXNA3. The involvement of RNA-binding protein quaking (QKI) in the regulation of NGC expression was investigated using monocytes and macrophages from a QKI haplo-insufficient patient and her healthy sibling. This revealed a positive correlation of SEMA7A expression with QKI expression. In silico analysis of 3′UTRs of NGCs proposed the competitive binding of QKI to proximal microRNA targeting sites as the mechanism of QKI-dependent regulation of SEMA7A. RNA immunoprecipitation confirmed an interaction of QKI with the 3′UTR of SEMA7A. Loss of SEMA7A resulted in monocyte differentiation towards a more anti-inflammatory macrophage. Taken together, the axonal guidance pathway is regulated during monocyte-to-macrophage differentiation, and the regulation is in line with the necessary functional adaption for the specialised role of macrophages.

scholarly journals Association of polymorphisms in the SLIT2 axonal guidance gene with anger in suicide attempters

2009 ◽  
Vol 15 (1) ◽  
pp. 10-11 ◽  
Author(s):  
M Sokolowski ◽  
J Wasserman ◽  
D Wasserman
Keyword(s):  
Axonal Guidance ◽  
Suicide Attempters

scholarly journals Analysis of the Caenorhabditis elegans axonal guidance and outgrowth gene unc-33.

Genetics ◽  
1992 ◽  
Vol 132 (3) ◽  
pp. 675-689 ◽  
Author(s):  
W Li ◽  
R K Herman ◽  
J E Shaw
Keyword(s):  
Caenorhabditis Elegans ◽  
Gamma Ray ◽  
Protein A ◽  
Genomic Region ◽  
Axonal Guidance ◽  
Significant Similarity ◽  
Spliced Leader ◽  
Neuronal Processes ◽  
Type Size ◽  
Intermediate Size

Abstract Mutations in the unc-33 gene of the nematode Caenorhabditis elegans lead to severely uncoordinated movement, abnormalities in the guidance and outgrowth of the axons of many neurons, and a superabundance of microtubules in neuronal processes. We have cloned unc-33 by tagging the gene with the transposable element Tc4. Three unc-33 messages, which are transcribed from a genomic region of at least 10 kb, were identified and characterized. The three messages have common 3' ends and identical reading frames. The largest (3.8-kb) message consists of the 22-nucleotide trans-spliced leader SL1 and 10 exons (I-X); the intermediate-size (3.3-kb) message begins with SL1 spliced to the 5' end of exon V and includes exons V-X; and the smallest (2.8-kb) message begins within exon VII and also includes exons VIII-X. A gamma-ray-induced deletion mutation situated within exon VIII reduces the sizes of all three messages by 0.5 kb. The three putative polypeptides encoded by the three messages overlap in C-terminal sequence but differ by the positions at which their N termini begin; none has significant similarity to any other known protein. A Tc4 insertion in exon VII leads to alterations in splicing that result in three approximately wild-type-size messages: the Tc4 sequence and 28 additional nucleotides are spliced out of the two larger messages; the Tc4 sequence is trans-spliced off the smallest message such that SL1 is added 13 nucleotides upstream of the normal 5' end of the smallest message.

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