Protein kinase Cepsilon actin-binding site is important for neurite outgrowth during neuronal differentiation.
We have previously shown that protein kinase Cepsilon (PKCepsilon) induces neurite outgrowth via its regulatory domain and independently of its kinase activity. This study aimed at identifying mechanisms regulating PKCepsilon-mediated neurite induction. We show an increased association of PKCepsilon to the cytoskeleton during neuronal differentiation. Furthermore, neurite induction by overexpression of full-length PKCepsilon is suppressed if serum is removed from the cultures or if an actin-binding site is deleted from the protein. A peptide corresponding to the PKCepsilon actin-binding site suppresses neurite outgrowth during neuronal differentiation and outgrowth elicited by PKCepsilon overexpression. Neither serum removal, deletion of the actin-binding site, nor introduction of the peptide affects neurite induction by the isolated regulatory domain. Membrane targeting by myristoylation renders full-length PKCepsilon independent of both serum and the actin-binding site, and PKCepsilon colocalized with F-actin at the cortical cytoskeleton during neurite outgrowth. These results demonstrate that the actin-binding site is of importance for signals acting on PKCepsilon in a pathway leading to neurite outgrowth. Localization of PKCepsilon to the plasma membrane and/or the cortical cytoskeleton is conceivably important for its effect on neurite outgrowth.
Zeidman
Ruth
R
Department of Laboratory Medicine, Molecular Medicine, Lund University, Malmö University Hospital, 205 02 Malmö, Sweden.
Trollér
Ulrika
U
Raghunath
Arathi
A
Påhlman
Sven
S
Larsson
Christer
C
D000199:Actins / Q000378:metabolism*; D001665:Binding Sites; D002454:Cell Differentiation / Q000502:physiology; D003599:Cytoskeleton / Q000378:metabolism; D006801:Humans; D019044:Image Cytometry; D007527:Isoenzymes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D016501:Neurites / Q000502:physiology*; D009447:Neuroblastoma; D011487:Protein Conformation; D011493:Protein Kinase C / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051744:Protein Kinase C-epsilon; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013379:Substrate Specificity; D014162:Transfection; D014407:Tumor Cells, Cultured
D000199:Actins; D007527:Isoenzymes; D011993:Recombinant Fusion Proteins; C497255:PRKCE protein, human; D011493:Protein Kinase C; D051744:Protein Kinase C-epsilon