Bauer V W, Swaffield J C, Johnston S A, Andrews M T
Department of Genetics, North Carolina State University, Raleigh 27695-7614, USA.
Gene. 1996 Nov 28;181(1-2):63-9. doi: 10.1016/s0378-1119(96)00463-5.
We have identified a novel protein, CADp44, based on the analysis of cDNAs derived from the brainstem of the 13-lined ground squirrel, Spermophilus tridecemlineatus. CADp44 has an unmodified molecular mass of 44,178 Da and contains multiple functional domains, including a conserved ATPase domain (CAD) and a leucine zipper motif. We show that distinct regions of the CADp44 sequence are identical to a set of peptides prepared from a recently identified bovine protein, referred to as p42, which is found in the PA700 regulatory complex of the 26S proteasome (DeMartino et al., 1996). We also show that CADp44 is the functional homolog of the newly characterized Sug2 protein from the budding yeast, Saccharomyces cerevisiae (Russell et al., 1996). Consistent with its role as a component of the 26S proteasome, CADp44 mRNA is found in all ground squirrel tissues examined. Evolutionary relationships based on sequence analysis show that both CADp44 and yeast Sug2p are distinct from the other five CAD ATPases found in the PA700, and together comprise the sixth and newest CAD subunit of the regulatory complex of the 26S proteasome.
基于对来自三线松鼠（Spermophilus tridecemlineatus）脑干的cDNA的分析，我们鉴定出了一种新蛋白CADp44。CADp44的未修饰分子量为44,178道尔顿，包含多个功能域，包括一个保守的ATP酶结构域（CAD）和一个亮氨酸拉链基序。我们发现，CADp44序列的不同区域与一组由最近鉴定出的牛蛋白（称为p42）制备的肽相同，该蛋白存在于26S蛋白酶体的PA700调节复合物中（DeMartino等人，1996年）。我们还表明，CADp44是来自芽殖酵母（Saccharomyces cerevisiae）的新鉴定的Sug2蛋白的功能同源物（Russell等人，1996年）。与其作为26S蛋白酶体组分的作用一致，在所有检测的松鼠组织中都发现了CADp44 mRNA。基于序列分析的进化关系表明，CADp44和酵母Sug2p都与在PA700中发现的其他五个CAD ATP酶不同，它们共同构成了26S蛋白酶体调节复合物的第六个也是最新的CAD亚基。
