Characterization of three novel members of the XXXX SHAGGY-related protein kinase (ASK) multigene family.

@entity22596 @entity1472 @entity958 @entity35 @entity238 @entity1473
In this paper we report the characterization of three novel members of the @entity958 shaggy-related protein kinase (ASK) multigene family, named ASKdzeta (ASKzeta), ASKetha (ASKeta) and ASKiota (ASKiota). The proteins encoded by the ASK genes share a highly conserved catalytic protein kinase domain and show about 70% identity to @entity22596 ) from @entity238 and @entity35 respectively. SGG is an ubiquitous intracellular component of the wingless signalling pathway that establishes cell fate and/or pattern formation in @entity238 . At least ten different ASK genes are expected to be present per haploid genome of A. thaliana. Different @entity1472 - and @entity1473 -terminal extensions distinguish different ASK family members. Five ASK gene sequences were analysed and shown to be present as single-copy genes in the @entity958 genome. A comparison based on the highly conserved catalytic domain sequences of all known sequences of the GSK-3 subfamily of protein kinases demonstrated a clear distinction between the plant and the animal kinases. Furthermore, we established the presence of at least three distinct groups of plant homologues of SGG/GSK-3. These different groups probably reflect biochemical and/or biological properties of these kinases. The differential expression patterns of five ASK genes were accessed by northern and in situ hybridization experiments using gene-specific probes. While ASKzeta is expressed in the whole embryo during its development, ASKeta expression is limited to the suspensor cells. No signal was detected for ASKalpha, ASKgamma and ASKiota in developing embryos.
