Isolation of two genes encoding putative protein kinases regulated during Dictyostelium discoideum development.
Two Dictyostelium discoideum protein kinase(PK)-encoding cDNAs (Dd PK1 and Dd PK2) have been isolated by hybridization with an oligodeoxyribonucleotide derived from a highly conserved region of eukaryotic PKs. The two nucleotide (nt) sequences encode new putative serine/threonine-specific PKs. Dd PK1 is a partial cDNA covering the entire catalytic domain. The derived amino acid (aa) sequence is about 30% identical to both cAMP-dependent protein kinase (cAPK) and protein kinase C. The Dd PK2 sequence was extended through the isolation of a genomic fragment encoding a complete putative protein. A single intron is present, as deduced from sequence comparison with the cDNA. The catalytic domain appears more closely related to the catalytic subunit of cAPK (54% sequence identity). However, our nt sequence potentially codes for a much larger protein (648 vs. about 350 aa for most cAPKs) with a N-terminal half containing long homopolymers of threonines, glutamines and asparagines. Similar repeats occur at the C terminus of Dd PK1, Dd PK1 is expressed in vegetatively growing cells and during development. Dd PK1 RNA decreases after 6 h of starvation to re-accumulate once the cells have aggregated. Dd PK2 transcripts, present at a low amount in growing cells, rise upon starvation. A switch to a shorter form of transcripts occurs between 3 and 6 h into development.
Bürki
E
E
Swiss Experimental Cancer Research Center, ISREC, Epalinges, Switzerland.
Anjard
C
C
Scholder
J C
JC
Reymond
C D
CD
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004023:Dictyostelium / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D011494:Protein Kinases / Q000235:genetics*; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D011494:Protein Kinases