Abstract
Protein-tyrosine phosphatases (PTPs) are key regulators of the insulin receptor signal transduction pathway. We have performed a detailed analysis of PTP expression in the major human insulin target tissues or cells (liver, adipose tissue, skeletal muscle and endothelial cells). To obtain a representative picture, all tissues were analyzed by PCR using three different primer sets corresponding to conserved regions of known PTPs. A total of 24 different PTPs were identified. A multiprobe RNase protection assay was developed to obtain a semiquantitative measure of the expression levels of selected PTPs. Surprisingly, PTP-LAR, previously suggested to be a major regulator of the insulin receptor tyrosine kinase, was expressed in extremely low levels in skeletal muscle, whereas the related receptor-type PTP-sigma and PTP-alpha were expressed in relatively high levels in all four tissues. The low levels of LAR PTP mRNA in skeletal muscle were further confirmed by Northern blot analysis.
| Original language | English |
|---|---|
| Journal | FEBS Letters |
| Volume | 415 |
| Issue number | 3 |
| Pages (from-to) | 243-8 |
| Number of pages | 6 |
| ISSN | 0014-5793 |
| Publication status | Published - 6 Oct 1997 |
Keywords
- Adipose Tissue
- Blotting, Northern
- DNA Primers
- Endothelium, Vascular
- Gene Expression Regulation, Enzymologic
- Humans
- Isoenzymes
- Muscle, Skeletal
- Placenta
- Polymerase Chain Reaction
- Protein Tyrosine Phosphatases
- RNA Probes
- RNA, Messenger
- Receptor, Insulin
- Receptor-Like Protein Tyrosine Phosphatases, Class 4
- Receptors, Cell Surface
- Ribonucleases
- Signal Transduction