| First Author | Passalacqua M | Year | 1999 |
| Journal | Biochem J | Volume | 337 ( Pt 1) |
| Pages | 113-8 | PubMed ID | 9854032 |
| Mgi Jnum | J:51897 | Mgi Id | MGI:1327093 |
| Citation | Passalacqua M, et al. (1999) Protein kinase C-theta is specifically localized on centrosomes and kinetochores in mitotic cells. Biochem J 337(Pt 1):113-8 |
| abstractText | In this study we provide evidence that the protein kinase C (PKC)-straight theta isoenzyme is recruited on to the mitotic spindle in dividing murine erythroleukaemia (MEL) cells and associates specifically with centrosome and kinetochore structures. None of the other PKC isoenzymes (-alpha, -delta, -epsilon, -mu and -zeta) expressed by MEL cells shows this localization on the mitotic spindle. An identical subcellular distribution of PKC-straight theta is also observed in dividing murine P3 myeloma cells and human LAN-5 neuroblastoma cells, indicating that this PKC isoenzyme interacts with the mitotic apparatus in mammalian cells. In phorbol-ester-treated non-growing MEL cells, a rapid change in the intracellular distribution of PKC-straight theta occurs. Under these conditions, PKC-straight theta is translocated from the nuclear to the cytosolic cell compartment, an event that is accompanied by phosphorylation of the PKC-straight theta molecule and is followed by its down-regulation. The recovery of cell growth capacity results in the concomitant reappearance of PKC-straight theta. Furthermore, when MEL cells acquire the differentiated non-growing phenotype, the level of PKC-straight theta is reduced to less than 5%, suggesting that this PKC isoenzyme is no longer required. We propose that, unlike other members of the PKC family, PKC-straight theta may play a role in cell proliferation. |
