Alternative splicing : the pledge, the turn, and the prestige : the key role of alternative splicing in human biological systems

© The Author(s) 2017. This article is an open access publication. Open Access. This article is distributed under the terms of the Crea-tive Commons Attribution 4.0 International License (http://crea-tivecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Alternative pre-mRNA splicing is a tightly controlled process conducted by the spliceosome, with the assistance of several regulators, resulting in the expression of different transcript isoforms from the same gene and increasing both transcriptome and proteome complexity. The differences between alternative isoforms may be subtle but enough to change the function or localization of the translated proteins. A fine control of the isoform balance is, therefore, needed throughout developmental stages and adult tissues or physiological conditions and it does not come as a surprise that several diseases are caused by its deregulation. In this review, we aim to bring the splicing machinery on stage and raise the curtain on its mechanisms and regulation throughout several systems and tissues of the human body, from neurodevelopment to the interactions with the human microbiome. We discuss, on one hand, the essential role of alternative splicing in assuring tissue function, diversity, and swiftness of response in these systems or tissues, and on the other hand, what goes wrong when its regulatory mechanisms fail. We also focus on the possibilities that splicing modulation therapies open for the future of personalized medicine, along with the leading techniques in this field. The final act of the spliceosome, however, is yet to be fully revealed, as more knowledge is needed regarding the complex regulatory network that coordinates alternative splicing and how its dysfunction leads to disease. The authors are supported by: EMBO Installation Grant (3057), Investigador FCT Starting Grant (IF/00595/2014) and iMM Lisboa start-up funds to NLB-M; Postdoctoral fellowships by UNESCO-L’Oreal For Women in Science Program (ERI/NCS/FLP/CDC.13.94) and iMM/FCT/MEC/FEDER (IMM/BPD/45-2016, LISBOA-01-0145-FEDER-007391) to LG-P; Fundação para a Ciência e Tecnologia (FCT) PhD fellowships to MCB (PD/BD/105854/2014) and MA-F (PD/BD/128283/2017); Fundação AstraZeneca Innovate Competition Award to MA-F.