title: Preferential expression of the cDNA encoding the proteasome subunit during the growth/differentiation transition of Dictyostelium cells.
abstract: A proteasome subunit-1 gene (DAPS-1) was isolated as one preferentially expressed during the transition from growth to differentiation in Dictyostelium discoideum cells, using the differential display method. The DAPS-1 cDNA sequence with a length of 882 bp encodes a protein (Mr. 23.4 kDa) consisting of 213 amino acids. The deduced amino acid sequence of DAPS-1 showed 61% and 58% identity to the proteasome subunit Y of Xenopus laevis and Homo sapiens, respectively and 48% and 47% identity to the proteasome subunit LMP2 of Homo sapiens and Orizas latipes, respectively. Northern analysis revealed that a 1.0 kb of DAPS-1 mRNA is predominantly expressed during the early stage of differentiation induced by starvation. This seems to indicate that the DAPS-1 protein may be involved in proteolysis coupled with active exchange of the cellular protein composition during the phase-shift of Dictyostelium cells from the proliferative to differentiated state.
authors.affiliation: Biological Institute, Graduate School of Science, Tohoku University, Sendai, Aoba, 980-77, Japan.
authors.forename: S C
authors.initials: SC
authors.lastname: Chae
authors.forename: Y
authors.initials: Y
authors.lastname: Maeda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics*; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000737:chemistry*; D004023:Dictyostelium / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry*; D046988:Proteasome Endopeptidase Complex; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D009097:Multienzyme Complexes; D012333:RNA, Messenger; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex