Isoforms of Protei,n Kinase C during the Differentiation of Chick Limb Mesenchvme

계배 간충직세포 분화과정에서의 Protein Kinase C Isoform들의 변화

The present studies were undertaken to examine the activitites of PKC isoforms in cultures of chick limb mesenchvme. Micromass cultures were prepared using wing buds of stage 23/24 (Hamburger and Hamilton, 19511 chick embryo. The cells were homogenized and DEAE-cellulose column chromatography was performed to get fraction containing protein kinase C (PKC) activity. PKC isoforms were resolved with hvdroxyapatitie column chromatography. Profile of PKC isoforms of cultures were compared with that of rat brain. Activity of $PKC-\beta$ isoform was appeared at the early stage of chondrogenesis. On 3 daw of culture, activities of both PKC a and $\beta$ were observed with remarkable increase but no activity of y isoform was appeared. Treatment of phorbol-12-mvristate-13-acetate (PMA) (10-7 M) to the culture inhibited chondrosenesis and down-regulated a and $\beta$ isoforms. Staurosporine promoted chondro!genesis without any effect on PKC isioforms profile. These data indicate that PKC a and $\beta,$ especiallv $\beta$ isoform is related to chondrosenesis and the promoting effect of staurosporine on chondrogenesis is not related to PKC isoforms activities.