ISSN:
1432-1432
Keywords:
Sponges
;
Geodia cydonium
;
Serine/threonine kinases
;
Phylogeny
;
Molecular systematics
;
Molecular evolution
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Protein kinases C (PKCs) comprise closely related Ser/Thr kinases, ubiquitously present in animal tissues; they respond to second messengers, e.g., Ca2+ and/or diacylglycerol, to express their activities. Two PKCs have been sequenced fromGeodia cydonium, a member of the lowest multicellular animals, the sponges (Porifera). One spongeG. cydonium PKC, GCPKC1, belongs to the “novel” (Ca2+-independent) PKC (nPKC) subfamily while the second one, GCPKC2, has the hallmarks of the “conventional” (Ca2+-dependent) PKC (cPKC) subfamily. The alignment of the Ser/Thr catalytic kinase domains, of the predicted as sequences for these cDNAs with respective segments from previously reported sequences, revealed highest homology to PKCs from animals but also distant relationships to Ser/Thr kinases from protozoa, plants, and bacteria. However, a comparison of the complete structures of the sponge PKCs, which are-already-identical to those of nPKCs and cPKCs from higher metazoa, with the structures of protozoan, plant, and bacterial Ser/Thr kinases indicates that the metazoan PKCs have to be distinguished from the nonmetazoan enzymes. These data indicate that metazoan PKCs have a universal common ancestor which they share with the nonmetazoan Ser/Thr kinases with respect to the kinase domain, but they differ from them in overall structural composition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02339011
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