Research Overview

Fig 1: Co-localisation of rDNA and UBF in HeLa cells

Fig 2: Persistence of nucleolar organising regions in interphase and metaphase

The mammalian cell nucleus is a highly organized biological structure. In addition to containing the genome the nucleus is also the site of many essential processes, such as gene transcription, replication and repair of the genome. To coordinate these events the nucleus is highly compartmentalised and contains numerous nuclear bodies that have distinct functions. Determining how cells build such internal structures is a major goal of biology.

The nucleolus, the site of ribosome biogenesis, is the most prominent nuclear body in all eukaryotic cells and represents a paradigm for nuclear organisation. Nucleoli are comprised of a high concentration of proteins including transcription factors and RNA processing machinery associated with arrays of ribosomal RNA encoding genes, nucleolar organizer regions (NORs), distributed among a number of chromosomes.

Our aims are to elucidate the chromosomal context of NORs and determine how their structure facilitates nucleolar formation and coordination of multiple steps in rRNA maturation. This work has additional significance as control of ribosome biogenesis is intimately connected to cellular growth and proliferation and is disregulated in many human diseases including cancer.