Alteration of SC35 localization by transfection reagents

A.P. Damodaran (1) , T. Courthéoux (1) , Erwan Watrin (1) , Claude Prigent (1)

1 IGDR - Institut de Génétique et Développement de Rennes

Transfection is a powerful tool that enables introducing foreign nucleic acids into living cells in orderto study the function of a gene product. Ever since the discovery of transfection many side effects orartifacts caused by transfection reagents have been reported. In this report, we show that thetransfection reagent, JetPRIME alters the localization of the splicing protein SC35 widely used as anuclear speckle marker. We demonstrate that transfection of plasmids with JetPRIME leads toenlarged SC35 speckles and SC35 cytoplasmic granules. By contrast, transfection of the sameplasmid with Lipofectamine 3000 does not have any effect on SC35 localization. The formation ofSC35 cytoplasmic granules by JetPRIME-mediated transfection is independent of exogenousexpression by plasmid and although similar in morphology they are distinct from P-bodies and stressgranules. This method of transfection affected only SC35 and phosphorylated SR proteins but not thenuclear speckles. The JetPRIME-mediated transfection also showed compromised transcription incells with enlarged SC35 speckles. Our work indicates that the use of JetPRIME alters SC35localization and can affect gene expression and alternative splicing. Therefore, caution should beexercised when interpreting results after the use of a transient transfection system, particularly whenthe subject of the study is the function of a protein in the control of gene expression or mRNAsplicing.

Keywords: Cytoplasmic granules; JetPRIME; SC35; Speckles; Splicing; Transfection

Domains: Life Sciences [q-bio]

A.P. Damodaran, T. Courthéoux, Erwan Watrin, Claude Prigent. Alteration of SC35 localization by transfection reagents. Biochimica et Biophysica Acta - Molecular Cell Research, 2020, 1867 (4), pp.118650. ⟨10.1016/j.bbamcr.2020.118650⟩. ⟨hal-02500548⟩