Gab-1-mediated IGF-1 Signaling in IRS-1-deficient 3T3 Fibroblasts

IGF-1 mediated phosphorylation of specific IRS-1 serines in Ames dwarf fibroblasts is associated with longevity

Insulin/IGF-1 signaling involves phosphorylation/dephosphorylation of serine/threonine or tyrosine residues of the insulin receptor substrate (IRS) proteins and is associated with hormonal control of longevity determination of certain long-lived mice. The stimulation of serine phosphorylations by IGF-1 suggests there is insulin/IGF-1 crosstalk that involves the phosphorylation of the same serin...

Regulation of Insulin/igf-1 Signaling by Proteasome- Mediated Degradation of Irs-2

Association of insulin receptor substrate 1 (IRS-1) y895 with Grb-2 mediates the insulin signaling involved in IRS-1-deficient brown adipocyte mitogenesis.

We have recently generated immortalized fetal brown adipocyte cell lines from insulin receptor substrate 1 (IRS-1) knockout mice and demonstrated an impairment in insulin-induced lipid synthesis as compared to wild-type cell lines. In this study, we investigated the consequences of IRS-1 deficiency on mitogenesis in response to insulin. The lack of IRS-1 resulted in the inability of insulin-sti...

GPER1-mediated IGFBP-1 induction modulates IGF-1-dependent signaling in tamoxifen-treated breast cancer cells

Tamoxifen, a selective estrogen receptor modulator, is a commonly prescribed adjuvant therapy for estrogen receptor-α (ERα)-positive breast cancer patients. To determine if extracellular factors contribute to the modulation of IGF-1 signaling after tamoxifen treatment, MCF-7 cells were treated with IGF-1 in conditioned medium (CM) obtained from 4-OHT-treated MCF-7 cells and the accumulation of ...

Fulminant Type 1 Diabetes Mellitus in IRS-2 Deficient Mice

Type 1 diabetes mellitus (T1DM), one of two major forms of diabetes, results from nearly complete destruction of pancreatic beta (┚) cells. According to the classification of diabetes made by the American Diabetes Association, T1DM is divided into two subtypes: immunemediated (type 1A) and idiopathic (type 1B) (American Diabetes Association, 2008). Fulminant type 1 diabetes mellitus (FT1DM), wh...