Related Experiment Video
Updated: Mar 16, 2026
JUMPn: A Streamlined Application for Protein Co-Expression Clustering and Network Analysis in Proteomics
Published on: October 19, 2021
Different interactomes for p70-S6K1 and p54-S6K2 revealed by proteomic analysis
Isadora C B Pavan1, Sami Yokoo2, Daniela C Granato2
1Laboratory of Metabolic Disorders, School of Applied Sciences, University of Campinas, Limeira, São Paulo, Brazil.
Abstract:
S6Ks are major effectors of the mTOR (mammalian target of rapamycin) pathway, signaling for increased protein synthesis and cell growth in response to insulin, AMP/ATP levels, and amino acids. Deregulation of this pathway has been related to disorders and diseases associated with metabolism, such as obesity, diabetes, and cancer. S6K family is composed of two main members, S6K1 and S6K2, which comprise different isoforms resulted from alternative splicing or alternative start codon use. Although important molecular functions have been associated with p70-S6K1, the most extensively studied isoform, the S6K2 counterpart lacks information. In the present study, we performed immunoprecipitation assays followed by mass spectrometry (MS) analysis of FLAG-tagged p70-S6K1 and p54-S6K2 interactomes, after expression in HEK293 cells. Protein lists were submitted to CRAPome (Contaminant Repository for Affinity Purification) and SAINT (Significance Analysis of INTeractome) analysis, which allowed the identification of high-scoring interactions. By a comparative approach, p70-S6K1 interacting proteins were predominantly related to "cytoskeleton" and "stress response," whereas p54-S6K2 interactome was more associated to "transcription," "splicing," and "ribosome biogenesis." Moreover, we have found evidences for new targets or regulators of the S6K protein family, such as proteins NCL, NPM1, eIF2α, XRCC6, PARP1, and ILF2/ILF3 complex. This study provides new information about the interacting networks of S6Ks, which may contribute for future approaches to a better understanding of the mTOR/S6K pathway.
Insights
The mammalian target of rapamycin (mTOR) pathway regulates cell growth. This study reveals distinct protein interaction networks for S6K1 and S6K2, uncovering new targets and regulators for the S6K protein family.
Area of Science:
- Molecular Biology
- Cell Signaling
- Proteomics
Background:
- The mTOR pathway is crucial for cell growth and metabolism, with S6Ks as key effectors.
- Dysregulation of the mTOR/S6K pathway is linked to metabolic disorders like obesity, diabetes, and cancer.
- While p70-S6K1 is well-studied, the functions and interactome of S6K2 remain largely unknown.
Purpose of the Study:
- To elucidate the distinct protein interaction networks of p70-S6K1 and p54-S6K2.
- To identify novel targets and regulators associated with the S6K protein family.
- To deepen the understanding of the mTOR/S6K signaling pathway.
Main Methods:
- Immunoprecipitation assays using FLAG-tagged p70-S6K1 and p54-S6K2 expressed in HEK293 cells.
- Mass spectrometry (MS) analysis to identify interacting proteins (interactomes).
- Bioinformatic analysis using CRAPome and SAINT for high-scoring interaction identification.
Main Results:
- Comparative analysis revealed distinct interactomes for p70-S6K1 and p54-S6K2.
- p70-S6K1 interactome proteins are predominantly associated with cytoskeleton and stress response.
- p54-S6K2 interactome proteins are mainly linked to transcription, splicing, and ribosome biogenesis.
- Identified potential new targets/regulators including NCL, NPM1, eIF2α, XRCC6, PARP1, and ILF2/ILF3 complex.
Conclusions:
- This study provides novel insights into the distinct molecular functions of S6K1 and S6K2 through their unique interactomes.
- The findings highlight new potential targets and regulators, expanding the known network of the S6K protein family.
- Understanding these distinct networks contributes to a more comprehensive view of the mTOR/S6K pathway's role in cellular processes.
More Related Videos
Related Concept Videos
02:26Protein Networks
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
02:04Protein-protein Interfaces
01:33Proteomics
Proteomics is the study of proteomes' function. It involves the large-scale systematic study of the proteome to denote the protein complement expressed by a genome. Scientist Mark Wilkins coined the term...