RACK1, a PKC targeting protein, is exclusively localized to basal airway epithelial cells.
The novel isoform of protein kinase C (PKC), PKCepsilon, is an important regulator of ciliated cell function in airway epithelial cells, including cilia motility and detachment of ciliated cells after environmental insult. However, the mechanism of PKCepsilon signaling in the airways and the potential role of the PKCepsilon-interacting protein, receptor for activated C kinase 1 (RACK1), has not been widely explored. We used immunohistochemistry and Western blot analysis to show that RACK1 is localized exclusively to basal, non-ciliated (and non-goblet) bovine and human bronchial epithelial cells. Our immunohistochemistry experiments used the basal body marker pericentrin, a marker for cilia, beta-tubulin, and an airway goblet cell marker, MUC5AC, to confirm that RACK1 was excluded from differentiated airway cell subtypes and is only expressed in the basal cells. These results suggest that PKCepsilon signaling in the basal airway cell may involve RACK1; however, PKCepsilon regulation in ciliated cells uses RACK1-independent pathways.
Slager
Rebecca E
RE
Department of Internal Medicine, Pulmonary and Critical Care Medicine Section, University of Nebraska Medical Center, 985300 Nebraska Medical Center, Omaha, NE 68198-5300, USA.
Devasure
Jane M
JM
Pavlik
Jaqueline A
JA
Sisson
Joseph H
JH
Wyatt
Todd A
TA
D000818:Animals; D001980:Bronchi / Q000166:cytology / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D002923:Cilia / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D009363:Neoplasm Proteins / Q000378:metabolism*; D051744:Protein Kinase C-epsilon / Q000378:metabolism*; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000166:cytology / Q000378:metabolism*
D009363:Neoplasm Proteins; C419368:RACK1 protein, human; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D051744:Protein Kinase C-epsilon; D019204:GTP-Binding Proteins