Atypical isoenzymes of PKC-iota, -lambda, -mu: relative distribution in mouse foetal and neonatal organs.
PKC-iota, -lambda and -mu are recently cloned and characterized as members of the alternative group of this family of protein kinases. We performed an immunohistochemical study about the expression of PKC-iota, -lambda and -mu in tissues and organs of mouse foetuses and newborn mice, in order to evaluate their peculiar functions during the developmental stages. The specificity of the antibodies was tested by Western-blotting experiments with whole extracts from 15-day mouse foetuses or neonatal mice. Cryostat sections of mouse foetal and neonatal organs were reacted with monoclonal (anti -iota and -lambda) or polyclonal (anti -mu) antibodies. The staining intensity was expressed in standardized arbitrary units from 0 to 250. An almost general increasing expression from foetal to neonatal samples, with the highest immunostaining for PKC-mu, was observed in all investigated organs, thus suggesting that PKC atypical isoforms are quantitatively expressed with a significant relationship with the proceeding of developmental phases. Marked differences were revealed also as far as the distribution of these isoforms was concerned in well defined cell populations, particularly in lung, stomach and kidney. These results suggest that various cell populations, in important phases of proliferating and differentiating events, produce atypical PKC isoforms that are conceivably involved in regulating signal transducing events. Therefore, PKC-iota, -lambda, -mu isoforms may have well defined functions in regulating the growth or the program of cell proliferation and differentiation.
Bareggi
R
R
Dipartimento di Morfologia Umana Normale, Università di Trieste. bareggi@univ.trieste.it
Bratina
F
F
Grill
V
V
Narducci
P
P
Martelli
A M
AM
D000818:Animals; D000831:Animals, Newborn; D000918:Antibody Specificity; D015153:Blotting, Western; D005314:Embryonic and Fetal Development; D005333:Fetus / Q000201:enzymology*; D007091:Image Processing, Computer-Assisted; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000378:metabolism*; D051379:Mice; D011493:Protein Kinase C / Q000378:metabolism*; D014018:Tissue Distribution
D007527:Isoenzymes; D011493:Protein Kinase C