# Regulation of mRNA transcription by the Integrator complex

> **NIH NIH K99** · UNIVERSITY OF PENNSYLVANIA · 2020 · $90,000

## Abstract

PROJECT SUMMARY/ABSTRACT
Cells maintain homeostasis by responding to their environment through regulated transcriptional programs. For
many genes that are rapidly induced, RNA polymerase II (Pol II) is pre-bound in a paused state. Sensing of the
stimulus triggers the switch to productive Pol II elongation, thereby resulting in production of full-length
mRNAs. Promoter-proximal pausing events are common, but are not observed at all inducible genes, including
the metallothionein genes that are induced upon metal stress. As it is largely unclear how the rapid induction of
the Drosophila metallothionein A gene (MtnA) is controlled, I performed a high-throughput RNAi screen and
surprisingly found that the Integrator complex is a potent inhibitor of MtnA transcription. Integrator has a well-
established role in 3' end processing of snRNAs, but I find that it is also directly recruited to the MtnA gene
where it cleaves nascent MtnA transcripts to trigger transcription termination. The MtnA small RNAs are
degraded by the RNA exosome, but can function as potent inhibitors of MtnA transcription when they
accumulate. These data strongly suggest that Integrator cleavage provides an alternative mechanism to
Pol II pausing as it helps keep full-length MtnA expression off in basal conditions, while also allowing
Pol II to continuously engage the locus so that MtnA can be rapidly induced in response to metal
stress. During the mentored phase, I will gain new training in biochemistry and high-throughput sequencing
approaches to characterize the detailed mechanism by which Integrator-dependent premature termination
events are triggered at MtnA and across the genome. In Aim 1, I will use reporter assays and
immunoprecipitation experiments to determine how Integrator is recruited to the MtnA locus as well as how the
MtnA small RNAs interfere with host gene induction. In Aim 2, I will use RNA-seq approaches to identify
additional genes that are subjected to Integrator-dependent termination events. By examining sequence
features at these regulated loci, this aim will reveal common features that dictate where/why Integrator cleaves
to trigger transcription termination. In Aim 3, I will take full advantage of this training and determine in my own
laboratory how the Integrator complex can have different functional effects at different gene loci. In particular,
we will determine whether endonuclease activity is always required for Integrator function as well as address
whether Integrator is modular and exists as sub-complexes that have different functional roles. In the short
term, the proposed new training by my expert mentors will provide a strong foundation that I can continue to
build upon in my own independent laboratory as we reveal how Integrator impacts inducible transcriptional
events. The excellent training environment at UPenn will greatly facilitate the mentored research as well as
endow me with the necessary skills to successfully transition to an independent...

## Key facts

- **NIH application ID:** 9852606
- **Project number:** 5K99GM131028-02
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Deirdre Tatomer
- **Activity code:** K99 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $90,000
- **Award type:** 5
- **Project period:** 2019-02-01 → 2021-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9852606

## Citation

> US National Institutes of Health, RePORTER application 9852606, Regulation of mRNA transcription by the Integrator complex (5K99GM131028-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9852606. Licensed CC0.

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