Dictyostelium discoideum contains a family of calmodulin-related EF-hand proteins that are developmentally regulated.
A full-length genomic DNA fragment that codes for a novel EF-hand protein Dictyostelium discoideum was cloned and sequenced. The protein is composed of 168 amino acids and contains four consensus sequences that are typical for (Ca2+)-binding EF-hand domains. The protein sequence exhibits only minor similarities to other calmodulin-type proteins from Dictyostelium. The genomic DNA harbors two short introns; their positions suggest that the gene is unrelated to the EF-hand proteins from the calmodulin group. Northern blot analysis showed that the mRNA level was significantly increased during development. Polyclonal antibodies raised against the recombinant protein recognized in Western blots a protein of about 20 kDa. Like the mRNA, also the protein was more abundant in developing cells. Overlay experiments with 45Ca2+ indicated that the EF-hands in fact have (Ca2+)-binding activity. The recent description of CBP1, another calmodulin-type Dictyostelium protein that is upregulated during development [Coukell et al. (1995) FEBS Lett. 362, 342-346], suggests that D. discoideum contains a family of EF-hand proteins that have specific functions during distinct steps of development. We therefore designate the protein described in this report as CBP2.
André
B
B
Adolf-Butenandt-Institut/Zellbiologie, München, Germany.
Noegel
A A
AA
Schleicher
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D016384:Consensus Sequence; D016054:DNA, Protozoan / Q000032:analysis; D004023:Dictyostelium / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development; D017125:Genes, Protozoan / Q000235:genetics; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D015800:Protozoan Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D016053:RNA, Protozoan / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D002135:Calcium-Binding Proteins; D016054:DNA, Protozoan; D015800:Protozoan Proteins; D012333:RNA, Messenger; D016053:RNA, Protozoan; D011993:Recombinant Fusion Proteins; C099146:calcium-binding protein 2, Dictyostelium; D002118:Calcium