Review Article

Friend or Foe? The fascinating Tudor-SN protein

¹ Department of Biochemistry and Molecular Biology, Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, PR China
² Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Key Laboratory of Cellular and Molecular Immunology in Tianjin, Excellent Talent Project, Tianjin Medical University, Tianjin 300070, PR China
³ Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland
⁴ Tays Cancer Center, Tampere University Hospital, 33520 Tampere, Finland
⁵ HiLIFE, Helsinki Institute of Life Science, University of Helsinki, 00790 Helsinki, Finland
⁶ Fimlab Laboratories, Pirkanmaa Hospital District, 33520 Tampere, Finland

^* Corresponding authors: yangj@tmu.edu.cn (J. Yang), olli.silvennoinen@tuni.fi (O. Silvennoinen)

Received: 23 January 2023
Accepted: 14 February 2023

Abstract

Tudor-SN (Tudor staphylococcal nuclease), also known as p100 or SND1 (Staphylococcal nuclease and Tudor domain containing 1), is a structurally conserved protein with diverse functions. Emerging evidence indicates that Tudor-SN plays an essential role in both physiological and pathological processes. Under physiological conditions, Tudor-SN regulates DNA transcription, RNA splicing, RNA stability, RNA interference, and RNA editing, and it is essential for a series of cellular biological events, such as cell cycle progression, cell metabolism, and cell survival, in response to harmful stimuli; thus, Tudor-SN functions as a “friend” to the body. However, Tudor-SN is highly expressed in most tumor cells. As an oncoprotein, Tudor-SN is closely associated with the initiation, development, and metastasis of tumors; thus, Tudor-SN functions as a “foe” to the body. What is the potential mechanism by which Tudor-SN switches from its role as “friend” to its role as “foe”? In this study, we review and summarize the available evidence regarding Tudor-SN protein structure, expression, modification, and mutation to present a novel model of Tudor-SN role switching. This review provides a comprehensive insight into the functional significance of the Tudor-SN protein under physiological and pathological conditions as well as corresponding therapeutic strategies that target Tudor-SN.