- Lucía Jiménez Gómez, Carlos Amenábar Blázquez and Alba Orea Soufi members of the Molecular Mechanisms of Aging and Cancer research group, led by Wolfgang Link, participate in the publication of the book "FOXO Transcription Factors: Methods and Protocols" on FOXO transcription factors.
- The book, the second version of the successful volume published five years ago, describes a multitude of techniques on aspects of FOXO biology, which will serve as a guide for researchers in this and other fields, both skilled and unskilled.
FOXO transcription factors are members of the Forkhead box (FOX) protein family and have been recognized as key regulators of cellular homeostasis, longevity, and disease mechanisms in various organisms throughout evolution. Interest in FOXO transcription factors began in the 1990s with the identification of the Forkhead gene in Drosophila melanogaster, which was later linked to various human homologs. The term FOXO refers to “Forkhead box O” proteins, a subset of the larger FOX family.
A key finding in 1993 revealed that mutations in the daf-16 gene in C. elegans, homologous to mammalian FOXO and part of the insulin/IGF-1 signaling pathway, influenced lifespan. As more FOX proteins were discovered, the classification system included FOXO1, FOXO3, FOXO4, and FOXO6 as mammalian homologs of single FOXO proteins in Drosophila melanogaster (dFOXO) and C. elegans (daf-16). Since then, distinct yet overlapping roles of the four FOXO proteins have been revealed. In 2007, FOXOs were established as tumor suppressor proteins in mice with combined deletion of FOXO1, FOXO3, and FOXO4, and their role in stem cells was revealed in vivo.
Over the years to date, a considerable number of publications have identified FOXO transcription factors as being involved in the regulation of glucose and lipid metabolism gene expression, apoptosis, autophagy, cell cycle inhibition, stress resistance, DNA repair, angiogenesis, inflammation, immune response, pluripotency, and differentiation. Studies showed that FOXOs are regulated by post-translational modifications such as phosphorylation, acetylation, and ubiquitination, which affect their localization and activity.
Research into FOXO proteins has employed a broad variety of methods and technologies, including western blotting, immunoprecipitation, chromatin immunoprecipitation (ChIP), omics approaches like transcriptomics and proteomics, genetic models such as mutational studies in C. elegans and Drosophila, knockout and transgenic mouse models, in vitro gene knockout/knockdown techniques, and luciferase reporter assays, among others. These approaches have been used to understand the broad regulatory networks controlled by FOXO factors.
Five years ago, a much-noticed volume in the Methods in Molecular Biology series on FOXO transcription factors was published, providing state-of-the-art protocols to study the regulation and function of these proteins. However, the past few years have witnessed many new directions in FOXO research, and several new technologies have been adopted by the research field. These developments have enabled new approaches in FOXO research and warrant the publication of a second edition of the volume on FOXO transcription factors, edited by Wolfgang Link, with the contributions of Lucía Jiménez Gómez, Carlos Amenabar Blazquez and Alba Orea Soufi, members of Link’s research group at the Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM).
This new volume, with 18 chapters, includes updates of previous chapters and a number of new chapters, and is divided into five parts.
- Part I is dedicated to biochemical techniques used to analyze the phosphorylation status of FOXO proteins, identify FOXO binding partners, determine the expression of FOXO target genes, and assess FOXO-specific transcriptional activity.
- Part II highlights genetic techniques to identify functional domains and validate disease relevance.
- Part III focuses on biophysical and bioinformatic techniques to study the structure and dynamics of FOXO proteins, protein-protein interactions, and identify small-molecule modulators.
- Part IV provides insight into different fluorescence and imaging techniques to measure FOXO translocation and nuclear trapping dynamics upon compound treatment, investigate overlapping and isoform-specific functions of FOXO proteins, and use fluorescent tagging to perform pull-down assays.
- Lastly, Part V focuses on functional studies in model organisms, such as the planarian Schmidtea mediterranea and the nematode C. elegans, to characterize cell death regulation and lifespan and health span, respectively.
The second edition of FOXO Transcription Factors: Methods and Protocols will serve as a valuable guide for both experienced researchers and those new to the field. Additionally, we hope that the broad variety of techniques described in the book will enable researchers in other fields to explore aspects of FOXO biology, as well as help those looking to acquaint themselves with the forefront of this exciting field.