Loading...
Please wait, while we are loading the content...
Similar Documents
Regulation of Organelle Movement in Melanophores by Protein Kinase A (PKA), Protein Kinase C (PKC), and Protein Phosphatase 2A (PP2A)
| Content Provider | Semantic Scholar |
|---|---|
| Author | Reilein, Amy R. Tint, I. S. Peunova, Natalia Enikolopov, Grigori Gelfand, Vladimir I. |
| Copyright Year | 1998 |
| Abstract | We used melanophores, cells specialized for regulated organelle transport, to study signaling pathways involved in the regulation of transport. We transfected immortalized Xenopus melanophores with plasmids encoding epitope-tagged inhibitors of protein phosphatases and protein kinases or control plasmids encoding inactive analogues of these inhibitors. Expression of a recombinant inhibitor of protein kinase A (PKA) results in spontaneous pigment aggregation. alpha-Melanocyte-stimulating hormone (MSH), a stimulus which increases intracellular cAMP, cannot disperse pigment in these cells. However, melanosomes in these cells can be partially dispersed by PMA, an activator of protein kinase C (PKC). When a recombinant inhibitor of PKC is expressed in melanophores, PMA-induced pigment dispersion is inhibited, but not dispersion induced by MSH. We conclude that PKA and PKC activate two different pathways for melanosome dispersion. When melanophores express the small t antigen of SV-40 virus, a specific inhibitor of protein phosphatase 2A (PP2A), aggregation is completely prevented. Conversely, overexpression of PP2A inhibits pigment dispersion by MSH. Inhibitors of protein phosphatase 1 and protein phosphatase 2B (PP2B) do not affect pigment movement. Therefore, melanosome aggregation is mediated by PP2A. |
| Starting Page | 803 |
| Ending Page | 813 |
| Page Count | 11 |
| File Format | PDF HTM / HTML |
| DOI | 10.1083/jcb.142.3.803 |
| PubMed reference number | 9700167 |
| Journal | Medline |
| Volume Number | 142 |
| Alternate Webpage(s) | http://jcb.rupress.org/content/jcb/142/3/803.full.pdf |
| Alternate Webpage(s) | https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/99/2e/32982.PMC2148163.pdf |
| Alternate Webpage(s) | http://repository.cshl.edu/29925/1/Enikolopov_JCellBiol1998.pdf |
| Alternate Webpage(s) | http://ftp.ncbi.nlm.nih.gov/pub/pmc/99/2e/32982.PMC2148163.pdf |
| Alternate Webpage(s) | https://doi.org/10.1083/jcb.142.3.803 |
| Journal | The Journal of cell biology |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
