UMass Chan Medical School Faculty Publications

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology; RNA Therapeutics Institute; Graduate School of Biomedical Sciences

Publication Date


Document Type

Article Preprint


Amino Acids, Peptides, and Proteins | Biochemistry | Nucleic Acids, Nucleotides, and Nucleosides


Argonaute proteins use nucleic acid guides to find and bind specific DNA or RNA target sequences. Argonaute proteins can be found in all kingdoms of life, and play diverse biological functions including genome defense, gene regulation, and chromosome partitioning. Many Argonautes retain their ancestral endoribonuclease activity, cleaving the phosphodiester bond between target nucleotides t10 and t11. In animals, a specialized class of Argonautes, the PIWI proteins, use 21–35 nt PIWI-interacting RNAs (piRNAs) to direct transposon silencing, protect the germline genome, and regulate gene expression during gametogenesis1. The piRNA pathway is required for fertility in one or both sexes of nearly all animals. Both piRNA production and function require RNA cleavage catalyzed by PIWI proteins. Spermatogenesis in mice and other placental mammals requires three distinct, developmentally regulated PIWI proteins: MIWI (PIWIL1), MILI (PIWIL2), and MIWI2 (PIWIL4)24; the piRNA-guided endoribonuclease activities of MIWI and MILI are essential to produce functional sperm5,6. piRNA-directed silencing in mice, insects, and worms also requires Gametocyte-Specific Factor 1 (GTSF1), a PIWI-associated protein of unknown function712. Here, we report that GTSF1 potentiates the weak, intrinsic, piRNA-directed RNA cleavage activities of PIWI proteins, transforming them into efficient endoribonucleases. GTSF1 represents the first example of an auxiliary protein that potentiates the catalytic activity of an Argonaute protein.


Biochemistry, zinc-finger protein, GTSF1, endoribonucleases, PIWI proteins, PIWI-interacting RNAs (piRNAs)

Rights and Permissions

The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license.

DOI of Published Version



bioRxiv 2021.05.04.442675; doi: Link to preprint on bioRxiv.


This article is a preprint. Preprints are preliminary reports of work that have not been certified by peer review.

Journal/Book/Conference Title


Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.