Identification and characterization of an insulin receptor substrate 4-interacting protein in rat brain: Implications for longevity

Chiba, Takuya; Inoue, Daisuke; Mizuno, Aya; Komatsu, Toshimitsu; Fujita, Satoshi; Kubota, Haruaki; Tagliaro, Maria Luisa; Park, Seong Joon; Trindade, Lucas Siqueira; Hayashida, Takahiro; Hayashi, Hiroko; Yamaza, Haruyoshi; Higami, Yoshikazu; Shimokawa, Isao

doi:10.1016/j.neurobiolaging.2007.07.008

Cited by 19 publications

(16 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One way to distinguish between these possibilities might be to identify regulatory proteins that interact with each IRS protein. In addition to viral proteins, IRS4 interacts with the WD repeat protein WDR6 in rat brain; the non-receptor tyrosine kinase breast tumor kinase (Brk) in HEK293 cells; protein phosphatase 4, which is proposed to be involved in downregulating IRS4 in response to tumour necrosis factor-alpha; and ankyrin repeat and SOCS box containing protein 4 (Asb-4) [12], [31], [32], [33]. However, the relevance of these for the effects of IRS4 observed here is unclear.…”

Section: Discussionmentioning

confidence: 99%

Effect of IRS4 Levels on PI 3-Kinase Signalling

2013

View full text Add to dashboard Cite

Insulin receptor substrate 1 (IRS1) and IRS2 are well-characterized adapter proteins that relay signals from receptor tyrosine kinases to downstream components of signalling pathways. In contrast, the function of IRS4 is not well understood. IRS4 overexpression has been associated with acute lymphoblastic leukaemia and subungual exostosis, while point mutations of IRS4 have been found in melanomas. Here, we show that while IRS4 expression is low in most cancer cell lines, IRS4 mRNA and protein levels are markedly elevated in certain cells including the NCI-H720, DMS114, HEK293T and HEK293AAV lines. Surprisingly, IRS4 expression was also strongly induced when HEK293 cells were infected with retroviral particles and selected under puromycin, making IRS4 expression a potential off-target effect of retroviral expression vectors. Cells with high expression of IRS4 displayed high phosphatidylinositol (3,4,5)-trisphosphate (PIP3) levels, as well as elevated Akt and p70 S6 kinase activities, even in the absence of growth factors. PI 3-kinase (PI3K) signalling in these cells depends on IRS4, even though these cells also express IRS1/2. Knockdown of IRS4 also inhibited cell proliferation in cells with high levels of IRS4. Together, these findings suggest IRS4 as a potential therapeutic target for cancers with high expression of this protein.

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of IRS4 Levels on PI 3-Kinase Signalling

2013

View full text Add to dashboard Cite

show abstract

“…The cells were maintained in Dulbecco's modified minimum essential medium (D-MEM; Wako) supplemented with 10% fetal bovine serum (Sigma-Aldrich), isolation of protein samples were performed as previously described [15,16].…”

Section: Cell Culturementioning

confidence: 99%

Development of a bioassay to screen for chemicals mimicking the anti-aging effects of calorie restriction

Chiba

Tsuchiya

Komatsu

et al. 2010

Biochemical and Biophysical Research Communications

Self Cite

View full text Add to dashboard Cite

Suppression of the growth hormone/insulin-like growth factor-I pathway in Ames dwarf (DF) mice, and caloric restriction (CR) in normal mice extends lifespan and delays the onset of age-related disorders. In combination, these interventions have an additive effect on lifespan in Ames DF mice. Therefore, common signaling pathways regulated by DF and CR could have additive effects on longevity. In this study, we tried to identity the signaling mechanism and develop a system to assess pro-longevity status in cells and mice. We previously identified genes up-regulated in the liver of DF and CR mice by DNA microarray analysis. Motif analysis of the upstream sequences of those genes revealed four major consensus sequence motifs, which have been named dwarfism and calorie restriction-responsive elements (DFCR-REs). One of the synthesized DFCR-RE sequences bound to hepatocyte nuclear factor-4 (HNF-4), an important transcription factor involved in liver metabolism. Furthermore, using this sequence information, we developed a highly sensitive bioassay to identify chemicals mimicking the anti-aging effects of CR. When the reporter construct, containing an element upstream of a secreted alkaline phosphatase (SEAP) gene, was co-transfected with HNF-4 and its regulator peroxisome proliferator-activated receptor (PPAR) coactivator-1 (PGC-1), SEAP activity was increased compared with untransfected controls. Moreover, transient transgenic mice established using this construct showed increased SEAP activity in CR mice compared with ad libitum-fed mice. These data suggest that because of its rapidity, ease of use, and specificity, our bioassay will be more useful than the systems currently employed to screen for CR mimetics, which mimic the beneficial effects of CR. Our system will be particularly useful for high-throughput screening of natural and synthetic candidate molecules.

show abstract

“…It contains an IRS PTB domain, through which it can bind to phosphorylated proteins. IRS4 is known to interact with both Shp2 [30] and WDR6 [31], [32], [33], and all these proteins have been implicated in FGFR signalling [19], [20], [34].…”

Section: Resultsmentioning

confidence: 99%

Novel Binding Partners and Differentially Regulated Phosphorylation Sites Clarify Eps8 as a Multi-Functional Adaptor

et al. 2013

View full text Add to dashboard Cite

Eps8 is involved in both cell signalling and receptor trafficking. It is a known phosphorylation substrate for two proteins involved in the fibroblast growth factor receptor (FGFR) signalling pathway: the receptor itself and Src. Here we report a differential proteomic analysis of Eps8 aimed to identify specific FGFR and Src family kinase dependent phosphosites and co-associated phosphodependent binding partners. This study reveals a total of 22 Eps8 pTyr and pSer/Thr phosphorylation sites, including those that are dependent on Src family and FGFR kinase activity. Peptide affinity purification of proteins that bind to a selection of the pTyr phosphosites has identified a range of novel Eps8 binding partners including members of the intracellular vesicle trafficking machinery (clathrin and AP-2), proteins which have been shown to regulate activated receptor trafficking (NBR1 and Vav2), and proteins involved in receptor signalling (IRS4 and Shp2). Collectively this study significantly extends the understanding of Eps8 post-translational modification by regulated phosphorylation, identifies novel Eps8 binding partners implicated in receptor trafficking and signalling, and confirms the functions of Eps8 at the nexus of receptor signalling and vesicular trafficking.

show abstract

Identification and characterization of an insulin receptor substrate 4-interacting protein in rat brain: Implications for longevity

Cited by 19 publications

References 47 publications

Effect of IRS4 Levels on PI 3-Kinase Signalling

Effect of IRS4 Levels on PI 3-Kinase Signalling

Development of a bioassay to screen for chemicals mimicking the anti-aging effects of calorie restriction

Novel Binding Partners and Differentially Regulated Phosphorylation Sites Clarify Eps8 as a Multi-Functional Adaptor

Contact Info

Product

Resources

About