Yeast counterparts of subunits S5a and p58 (S3) of the human 26S proteasome are encoded by two multicopy suppressors of nin1-1
Yeast counterparts of subunits S5a and p58 (S3) of the human 26S proteasome are encoded by two multicopy suppressors of nin1-1
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DOI：
10.1091/mbc.8.1.171
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发表时间：
1997-01-01
影响因子：
3.3
通讯作者：
Tohe, A
中科院分区：
文献类型：
--
作者：
Kominami, K;Okura, N;Tohe, A
Nin 1 p是酿酒酵母（Saccharomycescerevisiae）26 S蛋白酶体的一个组成部分，在G（1）-S-期和G（2）-M边界激活Cdc 28 p激酶是必需的。通过利用温度敏感的表型的min 1 -1突变体，我们已经筛选了基因编码的蛋白质与相关功能Nin 1 p和克隆和表征两个新的多拷贝抑制子，SUN 1和SUN 2，的Nin 1 -1突变。SUN 1可以抑制nin 1无效突变，而SUN 2，一个必需的基因，不能。Sun 1 p是一个由268个氨基酸组成的蛋白质，它与拟南芥的MBP 1（人26 S蛋白酶体S5 a亚基的同源物）具有很强的相似性。Sun 1 P与S5 a和MBP 1一样结合泛素-溶菌酶缀合物。发现Sun 2 p（523个氨基酸）与人26 S蛋白酶体的p58亚基同源。克隆了编码p58组分的cDNA。此外，表达的衍生物的p58的N-末端150个氨基酸已被删除恢复的功能，一个无效的等位基因的SUN 2。在甘油密度梯度离心过程中，Sun 1 p和Sun 2 p都与已知的蛋白酶体组分共迁移。这些结果以及其他结构和功能研究表明，Sun 1 p和Sun 2 p都是酵母26 S蛋白酶体调控模块的组成部分。
Nin1p, a component of the 26S proteasome of Saccharomyces cerevisiae, is required for activation of Cdc28p kinase at the G(1)-S-phase and G(2)-M boundaries. By exploiting the temperature-sensitive phenotype of the min1-1 mutant, we have screened for genes encoding proteins with related functions to Nin1p and have cloned and characterized two new multicopy suppressors, SUN1 and SUN2, of the nin1-1 mutation. SUN1 can suppress a null nin1 mutation, whereas SUN2, an essential gene, does not. Sun1p is a 268-amino acid protein which shows strong similarity to MBP1 of Arabidopsis thaliana, a homologue of the S5a subunit of the human 26S proteasome. Sun1P binds ubiquitin-lysozyme conjugates as do S5a and MBP1. Sun2p (523 amino acids) was found to be homologous to the p58 subunit of the human 26S proteasome. cDNA encoding the p58 component was cloned. Furthermore, expression of a derivative of p58 from which the N-terminal 150 amino acids had been removed restored the function of a null allele of SUN2. During glycerol density gradient centrifugation, both Sun1p and Sun2p comigrated with the known proteasome components. These results, as well as other structural and functional studies, indicate that both Sun1p and Sun2p are components of the regulatory module of the yeast 26S proteasome.