High impact information on Orc6

• A two-hybrid screen revealed that Orc6 interacts with the Drosophila peanut (pnut), a member of the septin family of proteins important for cell division [1].
• Silencing of Orc6 expression with double-stranded RNA resulted in a formation of multinucleated cells and also reduced DNA replication [1].
• We report that the smallest of Drosophila origin recognition complex subunits, Orc6, was found in embryos and cell culture localized to the cell membrane and cleavage furrow during cell division as well as in the nucleus [1].
• These results suggest that Orc6 has evolved a domain critical mainly for cytokinesis [1].
• We report here that the smallest Drosophila ORC subunit, Orc6, is a DNA binding protein that is necessary for the DNA binding and DNA replication functions of ORC [2].

Biological context of Orc6

• Orc6 binds DNA fragments containing Drosophila origins of DNA replication and prefers poly(dA) sequences [2].
• We show that mutant Orc6 proteins do not associate with chromosomes in vivo and have dominant negative effects in Drosophila tissue culture cells [2].
• We propose that the abnormal subcellular distribution and segregation of ORC proteins in AD might compromise their physiological function in gene silencing and plasticity [3].
• ORC subunits might, thus, provide a direct molecular link between synaptic plasticity, DNA replication and cell death [3].
• ORC subunits in the mammalian brain and their homologes in Drosophila, however, have further been implicated in the regulation of structural neuronal plasticity and cognitive function [3].

References