Proteome changes in autosomal recessive primary microcephaly
Sami Zaqout1, Atef Mannaa2,3, Oliver Klein4,5
1Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar.
Background/Aim:
Autosomal recessive primary microcephaly (MCPH) is a rare and genetically heterogeneous group of disorders characterized by intellectual disability and microcephaly at birth, classically without further organ involvement. MCPH3 is caused by biallelic variants in the cyclin-dependent kinase 5 regulatory subunit-associated protein 2 gene CDK5RAP2. In the corresponding Cdk5rap2 mutant or Hertwig's anemia mouse model, congenital microcephaly as well as defects in the hematopoietic system, germ cells and eyes have been reported. The reduction in brain volume, particularly affecting gray matter, has been attributed mainly to disturbances in the proliferation and survival of early neuronal progenitors. In addition, defects in dendritic development and synaptogenesis exist that affect the excitation-inhibition balance. Here, we studied proteomic changes in cerebral cortices of Cdk5rap2 mutant mice.
Material And Methods:
We used large-gel two-dimensional gel (2-DE) electrophoresis to separate cortical proteins. 2-DE gels were visualized by a trained observer on a light box. Spot changes were considered with respect to presence/absence, quantitative variation and altered mobility.
Result:
We identified a reduction in more than 30 proteins that play a role in processes such as cell cytoskeleton dynamics, cell cycle progression, ciliary functions and apoptosis. These proteome changes in the MCPH3 model can be associated with various functional and morphological alterations of the developing brain.
Conclusion:
Our results shed light on potential protein candidates for the disease-associated phenotype reported in MCPH3.
Insights
Researchers investigated proteomic changes in the brains of mice with MCPH3, a condition linked to CDK5RAP2 gene variants. They found reduced levels of over 30 proteins involved in crucial cellular processes, offering insights into brain development defects.
Area of Science:
- Neuroscience
- Genetics
- Proteomics
Background:
- Autosomal recessive primary microcephaly (MCPH) is a rare genetic disorder causing intellectual disability and small head size.
- MCPH3 is specifically linked to variants in the CDK5RAP2 gene.
- Previous studies in mouse models showed microcephaly and other defects, with brain volume reduction attributed to impaired neuronal progenitor proliferation and survival.
Purpose of the Study:
- To investigate proteomic alterations in the cerebral cortex of Cdk5rap2 mutant mice, a model for MCPH3.
- To identify specific proteins affected by Cdk5rap2 deficiency that may contribute to the observed brain abnormalities.
Main Methods:
- Utilized large-gel two-dimensional gel (2-DE) electrophoresis for protein separation from mouse cerebral cortices.
- Visualized and analyzed protein spots for changes in presence, quantity, and mobility.
Main Results:
- Identified a significant reduction in over 30 proteins within the cerebral cortex of Cdk5rap2 mutant mice.
- Affected proteins are involved in critical cellular functions including cytoskeleton dynamics, cell cycle, ciliary function, and apoptosis.
- These proteomic changes correlate with functional and morphological alterations observed in the developing brain of the MCPH3 model.
Conclusions:
- The study identified key protein candidates potentially responsible for the phenotype associated with MCPH3.
- These findings contribute to understanding the molecular mechanisms underlying brain development defects in this genetic disorder.
