Mitochondrial origin-binding protein UMSBP mediates DNA replication and segregation in trypanosomes.
Kinetoplast DNA (kDNA) is the remarkable mitochondrial genome of trypanosomatids. Its major components are several thousands of topologically linked DNA minicircles, whose replication origins are bound by the universal minicircle sequence-binding protein (UMSBP). The cellular function of UMSBP has been studied in Trypanosoma brucei by using RNAi analysis. Silencing of the trypanosomal UMSBP genes resulted in remarkable effects on the trypanosome cell cycle. It significantly inhibited the initiation of minicircle replication, blocked nuclear DNA division, and impaired the segregation of the kDNA network and the flagellar basal body, resulting in growth arrest. These observations, revealing the function of UMSBP in kDNA replication initiation and segregation as well as in mitochondrial and nuclear division, imply a potential role for UMSBP in linking kDNA replication and segregation to the nuclear S-phase control during the trypanosome cell cycle.
Milman
Neta
N
Department of Parasitology, The Kuvin Center for the Study of Infectious and Tropical Diseases, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
Motyka
Shawn A
SA
Englund
Paul T
PT
Robinson
Derrick
D
Shlomai
Joseph
J
D000818:Animals; D048750:Cell Nucleus Division / Q000235:genetics; D020090:Chromosome Segregation / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D018503:Genome, Protozoan; D008928:Mitochondria / Q000378:metabolism*; D008938:Mitosis / Q000235:genetics; D011003:Ploidies; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D034622:RNA Interference; D014346:Trypanosoma brucei brucei / Q000235:genetics*
D004268:DNA-Binding Proteins; D015800:Protozoan Proteins; C095676:universal minicircle sequence binding protein, protozoan