Microcephalin: a causal link between impaired damage response signalling and microcephaly.
Mark O'Driscoll1, Andrew P Jackson, Penny A Jeggo
1Genome Damage and Stability Centre, University of Sussex, East Sussex, UK.
Cell Cycle (Georgetown, Tex.)
|November 15, 2006
Summary
Seckel Syndrome and Primary Microcephaly involve small head size. Mutations in ATR and MCPH1 genes disrupt DNA damage response and cell division, causing these developmental disorders.
Area of Science:
- Genetics
- Molecular Biology
- Developmental Biology
Background:
- Seckel Syndrome (SS) and Primary Microcephaly (MCPH) are characterized by severe microcephaly.
- ATR-Seckel Syndrome is linked to mutations in the ATR kinase, crucial for DNA damage response.
- MCPH1, associated with Primary Microcephaly, also plays a role in DNA damage pathways.
Purpose of the Study:
- To review recent studies on the genetic basis of microcephaly disorders.
- To discuss the roles of ATR and MCPH1 in DNA damage signaling and cell cycle regulation.
- To explore the relationship between these genes and the etiology of microcephaly.
Main Methods:
- Analysis of cell lines from patients with SS and MCPH.
- Investigating mutations in ATR and MCPH1 genes.
- Review of existing literature on DNA damage response pathways and mitotic entry regulation.
Main Results:
- Defective ATR signaling is observed in SS patients without ATR mutations, suggesting involvement of other ATR pathway components.
- MCPH1 functions in the ATR-dependent DNA damage response.
- MCPH1 also regulates mitotic entry independently of ATR, leading to premature chromosome condensation.
Conclusions:
- Mutations in ATR and MCPH1 disrupt critical cellular processes, leading to microcephaly.
- The ATR pathway and MCPH1 are key players in the etiology of Seckel Syndrome and Primary Microcephaly.
- Understanding these pathways offers insights into developmental brain size regulation.
Related Concept Videos
Notch Signaling Pathway
The Notch signaling pathway is a major intracellular signaling pathway that is highly conserved over a broad spectrum of metazoan species. It stands unique from other intracellular signaling mechanisms in animals because notch protein itself acts as the receptor as well as the primary signaling molecule.
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...
Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...


