Mutations in ORC1, encoding the largest subunit of the origin recognition complex, cause microcephalic primordial dwarfism resembling Meier-Gorlin syndrome.

Abstract

Studies into disorders of extreme growth failure (for example, Seckel syndrome and Majewski osteodysplastic primordial dwarfism type II) have implicated fundamental cellular processes of DNA damage response signaling and centrosome function in the regulation of human growth. Here we report that mutations in ORC1, encoding a subunit of the origin recognition complex, cause microcephalic primordial dwarfism resembling Meier-Gorlin syndrome. We establish that these mutations disrupt known ORC1 functions including pre-replicative complex formation and origin activation. ORC1 deficiency perturbs S-phase entry and S-phase progression. Additionally, we show that Orc1 depletion in zebrafish is sufficient to markedly reduce body size during rapid embryonic growth. Our data suggest a model in which ORC1 mutations impair replication licensing, slowing cell cycle progression and consequently impeding growth during development, particularly at times of rapid proliferation. These findings establish a novel mechanism for the pathogenesis of microcephalic dwarfism and show a surprising but important developmental impact of impaired origin licensing.

• Authors: Louise S Bicknell, Sarah Walker, Anna Klingseisen, Tom Stiff, Andrea Leitch, Claudia Kerzendorfer, Carol-Anne Martin, Patricia Yeyati, Nouriya Al Sanna, Michael Bober, Diana Johnson, Carol Wise, Andrew P Jackson, Mark O'Driscoll, Penny A Jeggo
• Journal: Nature genetics (Nat Genet) Vol. 43 Issue 4 Pg. 350-5 (Feb 27 2011) ISSN: 1546-1718 [Electronic] United States
• PMID: 21358633 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Mutant Proteins
• ORC1 protein, human
• Origin Recognition Complex
• Zebrafish Proteins
• DNA

Topics

• Adolescent
• Amino Acid Sequence
• Amino Acid Substitution
• Animals
• Base Sequence
• Child
• Child, Preschool
• Congenital Microtia
• Consanguinity
• DNA (genetics)
• Dwarfism (genetics)
• Ear (abnormalities)
• Female
• Genome-Wide Association Study
• Growth Disorders (genetics)
• Humans
• Infant
• Male
• Microcephaly (genetics)
• Micrognathism (genetics)
• Models, Genetic
• Models, Molecular
• Molecular Sequence Data
• Mutant Proteins (chemistry, genetics)
• Mutation, Missense
• Origin Recognition Complex (chemistry, deficiency, genetics)
• Patella (abnormalities)
• Pedigree
• Polymorphism, Single Nucleotide
• Protein Structure, Tertiary
• S Phase (genetics)
• Saudi Arabia
• Sequence Homology, Amino Acid
• Zebrafish (embryology, genetics)
• Zebrafish Proteins (deficiency, genetics)