Post-transcriptional Regulation of HTLV Gene Expression: Rex to the Rescue

Donna M D'Agostino; Ilaria Cavallari; Maria Grazia Romanelli; Vincenzo Ciminale

doi:10.3389/fmicb.2019.01958

Post-transcriptional Regulation of HTLV Gene Expression: Rex to the Rescue

Front Microbiol. 2019 Aug 22:10:1958. doi: 10.3389/fmicb.2019.01958. eCollection 2019.

Authors

Donna M D'Agostino¹, Ilaria Cavallari², Maria Grazia Romanelli³, Vincenzo Ciminale^{2

4}

Affiliations

¹ Department of Biomedical Sciences, University of Padova, Padua, Italy.
² Istituto Oncologico Veneto IOV - IRCCS, Padua, Italy.
³ Section of Biology and Genetics, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
⁴ Department of Surgery, Oncology and Gastroenterology, University of Padova, Padua, Italy.

Abstract

Human T-lymphotropic virus type 1 (HTLV-1) and other members of the Deltaretrovirus genus code for a regulatory protein named Rex that binds to the Rex-responsive element present on viral mRNAs. Rex rescues viral mRNAs from complete splicing or degradation and guides them to the cytoplasm for translation. The activity of Rex is essential for expression of viral transcripts coding for the virion components and thus represents a potential target for virus eradication. We present an overview of the functional properties of the HTLV-1 and HTLV-2 Rex proteins (Rex-1 and Rex-2), outline mechanisms controlling Rex function, and discuss similarities and differences in the sequences of Rex coded by HTLV-1, -2, -3, and -4 that may influence their molecular anatomy and functional properties.

Keywords: HTLV-1; HTLV-2; RNA export; Rex; splicing.

Publication types

Review