title: cDNA cloning and functional analysis of p44.5 and p55, two regulatory subunits of the 26S proteasome.
abstract: We have employed cDNA cloning to deduce the complete primary structures of p44.5 and p55, two subunits of PA700, a 700-kDa multisubunit regulatory complex of the human 26S proteasome. These polypeptides consist of 422 and 456 amino acids with calculated molecular masses of 47463 and 52903, and isoelectric points of 6.06 and 7.56, respectively. Computer-assisted homology analysis revealed high sequence similarities of p44.5 and p55 with yeast proteins whose functions are yet unknown. Disruption of the yeast genes, termed NAS4 and NAS5 (non-ATPase subunits 4 and 5), resulted in lethality, indicating that each of the two subunits is essential for proliferation of yeast cells.
authors.affiliation: Otsuka GEN Research Institute, Otsuka Pharmaceutical Co. Ltd, Tokushima, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Saito
authors.forename: T K
authors.initials: TK
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Shimada
authors.forename: T
authors.initials: T
authors.lastname: Fujiwara
authors.forename: C A
authors.initials: CA
authors.lastname: Slaughter
authors.forename: G N
authors.initials: GN
authors.lastname: DeMartino
authors.forename: N
authors.initials: N
authors.lastname: Tanahashi
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D004912:Erythrocytes / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry; D017353:Gene Deletion; D005800:Genes, Fungal / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D005656:Fungal Proteins; C085834:PA700 proteasome activator; D010446:Peptide Fragments; D011506:Proteins; D010447:Peptide Hydrolases; D012697:Serine Endopeptidases; C036813:lysyl endopeptidase; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease