Fouts D L, Stryker G A, Gorski K S, Miller M J, Nguyen T V, Wrightsman R A, Manning J E
Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697-3900, USA.
J Biol Chem. 1998 Aug 21;273(34):21846-55. doi: 10.1074/jbc.273.34.21846.
The major structural proteins present in the paraflagellar rod of Trypanosoma cruzi migrate on SDS-polyacrylamide gels as two distinct electrophoretic bands. The gene encoding a protein present in the faster migrating band, designated PAR 2, has been identified previously. Here we report the isolation and partial characterization of three genes, designated par 1, par 3, and par 4, that encode proteins present in the two paraflagellar rod protein bands. Peptide-specific polyclonal antibodies and monoclonal antibodies against the four proteins encoded by these genes shows that PAR 1 and PAR 3 are present only in the slower migrating paraflagellar rod band, and that PAR 2 and PAR 4 are present only in the faster migrating band. Analysis of the nucleotide sequence of these genes and the amino acid sequence of the conceptual proteins encoded by them indicates that par 2 shares high sequence similarity with par 3 and both are members of a common gene family, of which par 1 may be a distant member. Analysis of gene copy number and steady-state RNA levels suggest that the close stoichiometric ratio of the four PAR proteins is likely maintained by homeostatic regulation of RNA levels rather than gene dosage.
克氏锥虫副鞭毛杆中的主要结构蛋白在SDS-聚丙烯酰胺凝胶上迁移形成两条不同的电泳带。先前已鉴定出编码存在于迁移较快条带中的一种蛋白（命名为PAR 2）的基因。在此，我们报告了三个基因（命名为par 1、par 3和par 4）的分离及部分特征分析，这些基因编码存在于两条副鞭毛杆蛋白带中的蛋白。针对这些基因所编码的四种蛋白的肽特异性多克隆抗体和单克隆抗体表明，PAR 1和PAR 3仅存在于迁移较慢的副鞭毛杆条带中，而PAR 2和PAR 4仅存在于迁移较快的条带中。对这些基因的核苷酸序列及其所编码的概念性蛋白的氨基酸序列分析表明，par 2与par 3具有高度序列相似性，二者均为一个共同基因家族的成员，par 1可能是该家族的远亲成员。基因拷贝数和稳态RNA水平分析表明，四种PAR蛋白紧密的化学计量比可能是通过RNA水平的稳态调节而非基因剂量来维持的。
