Spaceflight Activates Protein Kinase C Alpha Signaling and Modifies the Developmental Stage of Human Neonatal Cardiovascular Progenitor Cells

2018 ◽  
Vol 27 (12) ◽  
pp. 805-818 ◽  
Author(s):  
Jonathan Baio ◽  
Aida F. Martinez ◽  
Leonard Bailey ◽  
Nahidh Hasaniya ◽  
Michael J. Pecaut ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Developmental Stage ◽  
Progenitor Cells ◽  
Kinase C ◽  
Protein Kinase C Alpha

Protein kinase C-α isoform is involved in erythropoietin-induced erythroid differentiation of CD34+ progenitor cells from human bone marrow

Blood ◽  
2000 ◽  
Vol 95 (2) ◽  
pp. 510-518 ◽  
Author(s):  
June Helen Myklebust ◽  
Erlend B. Smeland ◽  
Dag Josefsen ◽  
Mouldy Sioud
Keyword(s):  
Bone Marrow ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Progenitor Cells ◽  
Erythroid Differentiation ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Kinase C ◽  
Pkc Isoforms ◽  
Cd34 Cells

Protein kinase C (PKC) is a family of serine/threonine protein kinases involved in many cellular responses. Although the analysis of PKC activity in many systems has provided crucial insights to its biologic function, the precise role of different isoforms on the differentiation of normal hematopoietic progenitor cells into the various lineages remains to be investigated. The authors have assessed the state of activation and protein expression of PKC isoforms after cytokine stimulation of CD34+ progenitor cells from human bone marrow. Freshly isolated CD34+ cells were found to express PKC-, PKC-β2, and PKC-ɛ, whereas PKC-δ, PKC-γ, and PKC-ζ were not detected. Treatment with erythropoietin (EPO) or with EPO and stem cell factor (SCF) induced a predominantly erythroid differentiation of CD34+ cells that was accompanied by the up-regulation of PKC- and PKC-β2 protein levels (11.8- and 2.5-fold, respectively) compared with cells cultured in medium. Stimulation with EPO also resulted in the nuclear translocation of PKC- and PKC-β2 isoforms. Notably, none of the PKC isoforms tested were detectable in CD34+ cells induced to myeloid differentiation by G-CSF and SCF stimulation. The PKC inhibitors staurosporine and calphostin C prevented EPO-induced erythroid differentiation. Down-regulation of the PKC-, PKC-β2, and PKC-ɛ expression by TPA pretreatment, or the down-regulation of PKC- with a specific ribozyme, also inhibited the EPO-induced erythroid differentiation of CD34+ cells. No effect was seen with PKC-β2–specific ribozymes. Taken together, these findings point to a novel role for the PKC- isoform in mediating EPO-induced erythroid differentiation of the CD34+ progenitor cells from human bone marrow.

scholarly journals Association of protein kinase-C-alpha with cytoplasmic vesicles in melanoma cells.

1996 ◽  
Vol 44 (2) ◽  
pp. 177-182 ◽  
Author(s):  
J Timar ◽  
B Liu ◽  
R Bazaz ◽  
K V Honn
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Fluid Phase ◽  
Subcellular Fractionation ◽  
Melanoma Cells ◽  
Kinase C ◽  
Cytoplasmic Vesicles ◽  
Protein Kinase C Alpha ◽  
Pkc Alpha

In B16a melanoma cells, protein kinase-C-alpha (PKC alpha) is immunomorphologically associated with cytoplasmic vesicles in addition to the previously observed locations (plasma membrane, cytoskeleton, nucleus), as detected with monoclonal antibody (MAb) MC3a. Subcellular fractionation indicated that the authentic 80-KD protein as well as PKC activity can be detected in several particulate fractions except for L2, which contains dense lysosomes. The highest PKC activity is associated with the cytosol-ultralight vesicles and the L1 fraction (containing plasma membrane, endosomes, and the Golgi apparatus). Both of these fractions contained the fluid-phase endocytosis marker peroxidase, indicating that PKC alpha, in addition to other subcellular structures, is most probably associated with endosomal membranes in B16a melanoma cells.

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