Related Experiment Video
Updated: Apr 5, 2026
16:01
Investigating Mast Cell Secretory Granules; from Biosynthesis to Exocytosis
Published on: January 26, 2015
13.8K
ϒ-secretase and LARG mediate distinct RGMa activities to control appropriate layer targeting within the optic tectum
P Banerjee1,2, H Harada1,2, N G Tassew1,2
1Genetics and Development and Vision Divisions, Toronto Western Research Institute, Krembil Discovery Tower, KDT-8-418, 60 Leonard Street, Toronto, ON, Canada M5T 2S8.
Cell Death and Differentiation
|August 22, 2015
Summary
Two RGMa peptides, C-RGMa and N-RGMa, guide retinal axons to specific optic tectum layers via distinct molecular pathways, revealing crucial mechanisms for precise neural mapping.
Area of Science:
- Neuroscience
- Molecular Biology
- Developmental Biology
Background:
- Understanding retino-tectal mapping is crucial for neural development.
- Specific molecular determinants guiding retinal projections to optic tectum layers remain unclear.
Purpose of the Study:
- To elucidate the distinct molecular mechanisms by which C-RGMa and N-RGMa regulate axonal growth and targeting in the developing optic tectum.
Main Methods:
- Investigated the roles of C-RGMa and N-RGMa in axonal growth regulation.
- Utilized overexpression of C-RGMa, N-RGMa, and dominant-negative LARG (LARG-PDZ).
- Examined the involvement of the LARG/Rho/Rock pathway and Neogenin intracellular domain (NeICD)/LMO4 pathway.
Main Results:
- C-RGMa inhibits axonal growth via the LARG/Rho/Rock pathway, acting as a barrier to deeper tectal layers.
- N-RGMa utilizes NeICD and LMO4, functioning as a repulsive guidance molecule.
- Overexpression studies demonstrated layer-specific effects on axonal projections.
Conclusions:
- C-RGMa and N-RGMa employ independent intracellular pathways to differentially regulate axonal growth and targeting.
- These findings reveal novel mechanisms for precise retinal projection targeting within the optic tectum.
Related Concept Videos
01:22Activation and Inactivation of G Proteins
12.5K
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
12.5K
01:14Rab Proteins
5.4K
Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
5.4K
01:33Overview of Secretory Vesicles
10.0K
Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
10.0K