Requirement of PI3-kinase activity for the nuclear transport of prolactin in cloned murine T lymphocytes.
The murine T-cell clone, L2, requires both IL2 and PRL to proliferate. Proliferation and selected IL2-driven gene expression are blocked by treatment with rapamycin. Since prolactin translocation to the nucleus is IL2 dependent and required for proliferation, experiments were performed to identify activation pathways that might be involved in nuclear transport and proliferation. L2 cells were stimulated with IL2 in the presence and absence of the mTOR inhibitor rapamycin, PI3-kinase inhibitors (wortmannin, LY294002), the p38 MAP kinase inhibitor SB203580 and the vitamin D analog calcipotriol. The immunosuppressant rapamycin markedly inhibited IL2-induced proliferation and prolactin translocation to the nucleus. Similarly, wortmannin and LY294002 inhibited IL2-induced proliferation and markedly decreased the amount of prolactin transported to the nucleus. SB203580 and calcipotriol partially inhibited IL2-induced proliferation but had no effect on prolactin translocation. None of the inhibitors affected Lucifer Yellow uptake indicating that rapamycin, wortmannin and LY294002 did not inhibit early endosomal formation but rather worked to inhibit prolactin translocation at a later point in the retrograde transport pathway.
Belkowski
S M
SM
Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Levine
J E
JE
Prystowsky
M B
MB
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000276:immunology; D002117:Calcitriol / Q000031:analogs & derivatives / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002467:Cell Nucleus / Q000276:immunology / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D002999:Clone Cells; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007376:Interleukin-2 / Q000276:immunology / Q000494:pharmacology; D007546:Isoquinolines / Q000493:pharmacokinetics; D051379:Mice; D009025:Morpholines / Q000494:pharmacology; D019913:Nuclear Localization Signals / Q000276:immunology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D020123:Sirolimus / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000201:enzymology* / Q000276:immunology; D000077191:Wortmannin
D000730:Androstadienes; D000970:Antineoplastic Agents; D002867:Chromones; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D007546:Isoquinolines; D009025:Morpholines; D019913:Nuclear Localization Signals; C055085:calcipotriene; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D011388:Prolactin; C017475:lucifer yellow; D019869:Phosphatidylinositol 3-Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002117:Calcitriol; D020123:Sirolimus; D000077191:Wortmannin