Integrator · Molecular and Functional analysis of the Integrator complex

The C-terminal domain (CTD) of RNA polymerase II (RNAPII) is essential for transcriptional regulation and RNA processing of protein coding genes. A large body of data also implicates the CTD in the transcription and processing of RNAPII-dependant spliceosomal U small nuclear RNAs (U1 to U5 snRNAs). Recently, we discovered a RNA polymerase II complex that contains at least twelve novel subunits, termed the Integrator complex, in addition to core RNAPII subunits. Two of these subunits display similarities to the subunits of the cleavage and polyadenylation specificity factor (CPSF) complex. We showed that the Integrator is recruited to the U1 and U2 snRNA genes and mediates the 3’-end processing of their transcript. The Integrator complex is evolutionarily conserved in metazoans and directly interacts with the CTD of the RNA polymerase II large subunit. This proposal is focused on providing a thorough physical and functional characterization of the Integrator complex. Aim1 will identify the interactions existing between the different subunits of the Integrator complex and between Integrator and the CTD of the RNAPII. Aim2 describes a detailed functional analysis of Integrator in transcriptional regulation and processing of the U snRNAs. Aim3 extends this work by the exploration of other potential targets for the Integrator complex. Elucidation of the mechanisms through which small nuclear RNAs are transcribed and processed is of seminal importance in understanding regulation of gene expression and growth control. Indeed, aberrant regulation of small nuclear RNA processing could result in defective messenger RNA processing through deregulation of the spliceosome, potentially leading to expression of aberrant proteins and adverse outcomes such as cellular transformation and oncogenesis.