Molecular cloning of cDNA for proteasomes (multicatalytic proteinase complexes) from rat liver: primary structure of the largest component (C2)

作者：Tsutomu Fujiwara, Keiji Tanaka, Atsushi Kumatori, Sadahito Shin, Tetsuro Yoshimura, Akira Ichihara, Fuminori Tokunaga, Rie Aruga, Sadaaki Iwanaga · 发表于：Biochemistry · 年份：1989 · DOI：10.1021/bi00444a028 · 被引用次数：87 · 研究领域：Ubiquitin and proteasome pathways、Peptidase Inhibition and Analysis、Galectins and Cancer Biology

Proteasomes (multicatalytic proteinase complexes) from rat liver are composed of at least 13 nonidentical components [Tanaka, K., Yoshimura, T., Ichihara, A., Ikai, A., Nishigai, M., Morimoto, M., Sato, M., Tanaka, N., Katsube, Y., Kameyama, K., & Takagi, T. (1988) J. Mol. Biol. 203, 985-996]. The nucleotide sequence of one major component (C2) of the proteasomes has been determined from a recombinant cDNA clone isolated by screening a rat liver cDNA library with a mixture of synthetic deoxyribonucleotides as a probe. The sequence was composed of 1174 nucleotides including a coding region for the entire protein and noncoding regions of both the 5'- and 3'-sides. The polypeptide deduced from the open reading frame consisted of 263 amino acid residues, and its molecular weight was calculated to be 29,516. The partial amino acid sequences of several fragments (approximately 45% of the total residues), which were obtained by cleavage of C2 with lysyl endopeptidase and cyanogen bromide, were determined by automated Edman degradation and found to be in complete accordance with those deduced from the cDNA sequence. The amino acid composition of C2, determined by chemical analysis, was also consistent with that deduced from the cDNA sequence, indicating that the cloned cDNA actually encoded component C2. Computer analysis revealed little structural similarity of C2 to other proteins reported so far. Northern blot hybridization analyses showed that the mRNA encoding this novel protein...