The effect of thyroid status on the in vitro autophosphorylation of the insulin receptors was studied in triton-solubilized adipocyte plasma membranes obtained from normal and thyroidectomized rats. Thyroidectomy results in an increase (two to three times) of the in vitro insulin-dependent phosphorylation of the insulin beta-subunit receptor. Phosphorylation occurred on tyrosine residues. In vivo injection of triiodothyronine to thyroidectomized rats restored plasma membranes autophosphorylation of the beta-subunit to the values obtained for control euthyroid rats. This effect was independent of the number and affinity of the insulin receptors, which were not modified regardless of thyroid status.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0006-291x(85)90293-1 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Mechanistic studies of PFKFB2 reveals a novel inhibitor of its kinase activity.
bioRxiv
December 2024
Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK.
The 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase (PFKFB) family of proteins are bifunctional enzymes that are of clinical relevance because of their roles in regulating glycolysis in insulin sensitive tissues and cancer. Here, we sought to express recombinant PFKFB2 and develop a robust protocol to measure its kinase activity. These studies resulted in the unexpected finding that bacterially expressed PFKFB2 is phosphorylated on Ser483 but is not a result of autophosphorylation.
View Article and Find Full Text PDFβ-integrin controls IGF-1R internalization and intracellular signaling.
J Biol Chem
November 2024
Cell Biology Laboratory, School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland. Electronic address:
Cell adhesion-dependent phosphorylation of insulin-like growth factor 1 receptor (IGF-1R) on its C-terminal tail (CT) at Tyr promotes receptor internalization and Golgi accumulation. We previously proposed that this phosphorylation is associated with cell migration and cancer aggressiveness, distinguishing IGF-1R activity from that of insulin receptor, which lacks these tyrosines. Here, we further investigated how adhesion signaling influences IGF-1R location and activity in migratory cancer cells and R- fibroblasts.
View Article and Find Full Text PDFRecent update on IGF-1/IGF-1R signaling axis as a promising therapeutic target for triple-negative breast cancer.
Pathol Res Pract
November 2024
Molecular Signaling & Drug Discovery Laboratory, Department of Biochemistry, Central University of Punjab, Guddha, Bathinda, Punjab 151401, India.
Insulin-like growth factor 1/Insulin-like growth factor 1-receptor (IGF-1/IGF-1R) pathway is highly breast cancer subtype context-dependent. Triple-negative breast cancer (TNBC) is an aggressive, highly metastatic cancer showing early recurrence and poor prognosis. High expression of IGF-1 and its receptor IGF-1R, their interaction, autophosphorylation, and activation of intracellular signaling cascades have been significantly associated with TNBC pathophysiology.
View Article and Find Full Text PDFSpontaneous Dimerization and Distinct Packing Modes of Transmembrane Domains in Receptor Tyrosine Kinases.
Biochemistry
October 2024
Department of Chemical Engineering and Bioengineering, University of New Hampshire, Durham, New Hampshire 03824, United States.
The insulin receptor (IR) and the insulin-like growth factor-1 receptor (IGF1R) are homodimeric transmembrane glycoproteins that transduce signals across the membrane on binding of extracellular peptide ligands. The structures of IR/IGF1R fragments in apo and liganded states have revealed that the extracellular subunits of these receptors adopt Λ-shaped configurations to which are connected the intracellular tyrosine kinase (TK) domains. The binding of peptide ligands induces structural transitions in the extracellular subunits leading to potential dimerization of transmembrane domains (TMDs) and autophosphorylation in TKs.
View Article and Find Full Text PDFEffects of heterologous kinase domains on growth factor receptor specificity.
Cell Signal
October 2024
Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA 11794; Department of Veterans Affairs Medical Center, Northport, NY 11768, USA. Electronic address:
Article Synopsis
- The study investigates the role of kinase domain specificity in receptor tyrosine kinases (RTKs) by creating chimeric receptors, replacing the kinase domains of IGF1R and EGFR with those from IR, Ron, or Src.
- Results showed that for some signaling processes, like interacting with IRS1, the type of kinase domain wasn't critical, while others, like autophosphorylation on EGFR, were dependent on the specific kinase.
- The findings suggest that RTK signaling quality relies on both the targeting of substrates and the unique properties of the kinase domains, with changes in domains affecting signaling reliability and receptor regulation.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!