First Author | Shirai Y | Year | 2011 |
Journal | Mol Biol Cell | Volume | 22 |
Issue | 8 | Pages | 1340-52 |
PubMed ID | 21346190 | Mgi Jnum | J:180539 |
Mgi Id | MGI:5306545 | Doi | 10.1091/mbc.E10-09-0754 |
Citation | Shirai Y, et al. (2011) Direct binding of RalA to PKCeta and its crucial role in morphological change during keratinocyte differentiation. Mol Biol Cell 22(8):1340-52 |
abstractText | During differentiation, keratinocytes undergo a dramatic shape change from small and round to large and flat, in addition to production of proteins necessary for the formation of epidermis. It has been shown that protein kinase C (PKC) eta is crucial for keratinocyte differentiation. However, its role in this process has yet to be fully elucidated. Here, we show that catalytic activity is not necessary for enlarged and flattened morphology of human keratinocytes induced by overexpression of PKCeta, although it is important for gene expression of the marker proteins. In addition, we identify the small G protein RalA as a binding partner of PKCeta, which binds to the C1 domain, an indispensable region for the morphological change. The binding led activation of RalA and actin depolymerization associated with keratinocyte differentiation. siRNA techniques proved that RalA is involved in not only the keratinocyte differentiation induced by PKCeta overexpression but also normal keratinocyte differentiation induced by calcium and cholesterol sulfate. These results provide a new insight into the molecular mechanism of cytoskeletal regulation leading to drastic change of cell shape. |