Transcription regulation in eukaryotes
Olga Calvo García. is Ph.D. in Biology (1993, University of Salamanca). Her Ph.D. studies were focused on RNAPIII transcription and translation initiation. Then during her postdoctoral stage at Columbia University in N. York (1999-2003) she worked on pre-mRNA processing and unveiled one of the first interactions between transcription initiation and polyadenylation complexes, making seminal and outstanding contributions to the nascent field of co-transcriptional processing. She also collaborated to discover the long-sought polyadenylation endonuclease, two decades after mRNAs polyadenylation was discovered. In 2004 she joint the “Centro de Investigación del Cancer” in Salamanca as a “Ramón y Cajal” scientist, where she finished the investigations started in N. York. Then, in 2007, she moved to the Institute of Functional Biology and Genomics (IBFG), where she initiated her research, now in the regulation of transcription. Since 2009 she has been a scientist of the CSIC and has been interested in the characterization of several important regulators of RNAPII transcription and phosphorylation, with milestones publications in the field. In addition, she has made contributions to the field of gene expression with relevant studies related to transcription termination of snoRNAs and RNAPI transcription.
She is currently interested in deciphering some of the mechanisms involved in the regulation of RNAPII phosphorylation and gene loop formation. Furthermore, she is studying snoRNAs transcription termination and factors that the three eukaryotic RNAPs might share.
- Araceli González Jiménez
- Carmen González Jiménez
- Manuel Jesús Alfonso Pérez
Regulation of gene expression is the result of the combined control of transcription and RNA processing in the nucleus and translation and mRNA decay in the cytoplasm. One of these processes, transcription of protein-encoding genes by RNA polymerase II (RNAPII), plays a central role in gene expression in all living organisms. RNAPII transcription is highly regulated at many steps, including initiation, elongation, and termination, and tightly coordinated and linked to many other nuclear functions in a complex web of connections. The central coordinator that directs this regulatory network is the RNAPII itself, being the carboxy-terminal domain (CTD) of its largest subunit, Rpb1, of particular importance. Thus, RNAPII-CTD phosphorylation regulates and coordinates the entire transcription cycle with pre-mRNA processing, mRNA transport, chromatin remodeling, and histone modifications. Therefore, RNAPII phosphorylation is one of the key processes in the regulation of gene expression in general. However, whether other RNAPII subunits are subjected to phosphorylation and their relevance in gene transcription is unknown. In the case of RNAPI and RNAPIII, which do not contain a CTD domain, little is known about their regulation by phosphorylation and whether this is a mechanism that could be used to connect and coordinate RNAPs activity. Consequently, deciphering the mechanisms underlying RNAPs phosphorylation regulation is crucial to understand gene expression regulation. Our research focuses on three main lines of research:
1) The molecular mechanisms underlying the transcription regulation of mRNAs, such as RNAPII phosphorylati4on and gene loops formation.
2) The regulation of Rpb4 and Rpb7 functions, unique and unconventional RNAPII subunits due to their versatility to function in different cellular compartments and many biological processes, from transcription in the nucleus to decay and translation in the cytosol.
3) The discovery of new factors shared by the three eukaryotic RNAPs.