We have investigated the pattern of expression of classical (α, βI, βII, γ), novel (δ) and atypical (ζ) protein kinase C (PKC) isoforms during the course of human hematopoietic differentiation along the closely related megakaryocytic and erythroid lineages. Using in situ immunofluorescence analysis, freshly isolated human pluripotent CD34+ hematopoietic progenitor cells expressed detectable amounts of all the PKC isoforms investigated. On the other hand, clear-cut differences in terms of PKC staining were noticed between cells belonging to the erythroid and megakaryocytic lineages, obtained after 9 days of serum-free liquid culture in the presence of specific growth factors. Specifically, 1) erythroid cells showed a very weak expression of PKC-α, -βI, -βII, and -γ, while megakaryocytes showed an enhanced expression of all classical PKC isoforms, predominantly confined to the cytoplasm; 2) the expression of PKC-δ increased in the cytoplasmic and nuclear compartments of both erythroid and megakaryocytic cells with respect to CD34+ cells; and 3) atypical PKC-ζ isoform showed a striking accumulation in the nucleus during both erythroid and megakaryocytic differentiation.
|Number of pages||8|
|Publication status||Published - 1999|
- Hematopoietic differentiation
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)