1. Cytokine Signaling

2. Types of receptors Protein tyrosine kinase receptors with intrinsic kinase activity –Insulin, EGF, PDGF, CSF-1 etc. Protein serine kinase receptors with intrinsic kinase activity –MIS, TGF , activin, inhibin etc. Receptors without intrinsic kinase activity –This is the large, heterogeneous group called the cytokine receptor super family G-protein coupled receptors and ion-gated receptors

3. Types of receptors

4. Protein tyrosine kinase receptors

5. PTK receptor activating MAP kinase pathway

6. PTK receptor activating Pi-3 kinase pathway

7. SH2 domain containing protein: recognition of phosphotyrosines

8. PTK signaling: 1 o and 2 o signals

9. Cytokine signaling mechanisms Cytokines represent a diverse number of molecules. The super family of cytokine receptors more specifically refers to those cytokines that signal via the Jak-STAT pathway These include Interleukins 2, 3, 4, 5, 6, 7, 9, 11, 12, 13, & 15, and G-CSF, LIF and the interferons In addition, growth hormone, prolactin, erythropoietin, leptin, thrombopoietin Many growth factor signal pathways cross-communicate with the STAT pathway.

11. General scheme for all MAP- kinase pathways

12. Receptor activation of intracellular signaling pathways

13. PTK vs. cytokine pathways

14. G-protein coupled receptors

15. Cytokines and Leydig cells Overview and significance of Immune-endocrine interactions in the regulation of Leydig cell function Immune-Endocrine control of Leydig cell function