The Mouse-Specific Splice Variant mRAGE_v4 Encodes a Membrane-Bound RAGE That Is Resistant to Shedding and Does Not Contribute to the Production of Soluble RAGE

PLoS One. 2016 Sep 21;11(9):e0153832. doi: 10.1371/journal.pone.0153832. eCollection 2016.

Abstract

The receptor for advanced glycation end-products (RAGE) is involved in the onset and progression of several inflammatory diseases. The RAGE primary transcript undergoes numerous alternative splicing (AS) events, some of which are species-specific. Here, we characterize the mouse-specific mRAGE_v4 splice variant, which is conserved in rodents and absent in primates. mRAGE_v4 derives from exon 9 skipping and encodes a receptor (M-RAGE) that lacks 9 amino acids between the transmembrane and the immunoglobulin (Ig) domains. RNA-Seq data confirm that in mouse lung mRAGE_v4 is the most abundant RAGE mRNA isoform after mRAGE, which codes for full-length RAGE (FL-RAGE), while in heart all RAGE variants are almost undetectable. The proteins M-RAGE and FL-RAGE are roughly equally abundant in mouse lung. Contrary to FL-RAGE, M-RAGE is extremely resistant to shedding because it lacks the peptide motif recognized by both ADAM10 and MMP9, and does not contribute significantly to soluble cRAGE formation. Thus, a cassette exon in RAGE corresponds to a specific function of the RAGE protein-the ability to be shed. Given the differences in RAGE AS variants between rodents and humans, caution is due in the interpretation of results obtained in mouse models of RAGE-dependent human pathologies.

Grants and funding

AR is supported by funding from Italian Ministry of Health for Young Researchers (GR-2010-2312693) and by Fondazione Monzino and Centro Cardiologico Monzino-IRCCS (Ricerca Corrente 2015-2017). GF acknowledges the financial support by a grant of the Deutsche Forschungsgemeinschaft and a Heisenberg fellowship (FR1488/5-2 and FR1488/3-2). MEB is supported by grant GR-2010-2312693 from the Italian Ministry of Health. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.