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Rab21 regulates caveolin-1-mediated endocytic trafficking to promote immature neurite pruning
Mima Shikanai1, Shiho Ito2,3, Yoshiaki V Nishimura4
1Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
EMBO Reports
|January 23, 2023
Summary
Clathrin and caveolin endocytosis pathways are distinct, not converging. Rab21, not Rab5, regulates caveolin-1, impacting neuronal development and neurite pruning.
Area of Science:
- Cell Biology
- Neuroscience
- Molecular Biology
Background:
- Transmembrane proteins internalize via clathrin- and caveolin-dependent endocytosis.
- These pathways were thought to converge on early endosomes and share Rab5 as a regulator.
Purpose of the Study:
- To investigate the differential regulation of clathrin- and caveolin-mediated endocytosis.
- To explore the distinct roles of Rab5 and Rab21 in these pathways within cortical neurons.
Main Methods:
- Localization studies of Rab5 and Rab21 in cortical neurons.
- Functional analysis through Rab21 suppression.
- Assessment of caveolin-1 levels and plasma membrane localization.
- Evaluation of neurite pruning in cortical neurons.
Main Results:
- Rab5 and Rab21 localize to distinct early endosome populations.
- Rab5 and Rab21 differentially regulate clathrin- and caveolin-mediated pathways, respectively.
- Rab21 suppression reduces caveolin-1 levels and perturbs neurite pruning.
- Evidence for heterogeneity in early endosomes.
Conclusions:
- Clathrin- and caveolin-mediated endocytosis pathways operate in parallel within early endosomes.
- These pathways exhibit distinct molecular regulation by Rab GTPases.
- Differential regulation impacts neuronal maturation processes like neurite pruning.
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