GOLGI RETENTION MECHANISM OF BETA-1,4-GALACTOSYLTRANSFERASE - MEMBRANE-SPANNING DOMAIN-DEPENDENT HOMODIMERIZATION AND ASSOCIATION WITH ALPHA-TUBULINS AND BETA-TUBULINS
GOLGI RETENTION MECHANISM OF BETA-1,4-GALACTOSYLTRANSFERASE - MEMBRANE-SPANNING DOMAIN-DEPENDENT HOMODIMERIZATION AND ASSOCIATION WITH ALPHA-TUBULINS AND BETA-TUBULINS
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DOI：
10.1074/jbc.270.20.12170
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发表时间：
1995-05-19
影响因子：
4.8
通讯作者：
FUKUDA, MN
中科院分区：
文献类型：
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作者：
YAMAGUCHI, N;FUKUDA, MN
最近对驻留在高尔基复合体中的蛋白质的研究表明，这些蛋白质的跨膜结构域在很大程度上是它们在高尔基复合体中保留的原因。我们发现，β-1，4-半乳糖基转移酶(GT)在体内形成同源二聚体和大的寡聚体，并且同源二聚体的形成依赖于跨膜结构域中的半胱氨酸和组氨酸残基。这些残基的双重突变，Cys(29)->；Ser和His(32)-->；Leu，废除了同源二聚化，同时减少了高尔基体的保留。GT和各种GT嵌合体与抗GT和抗报告分子抗体的免疫共沉淀表明，GT的大聚集体与α和β微管蛋白以及其他细胞蛋白有关。微管蛋白和GT之间的这种联系表明细胞骨架在高尔基体滞留机制中起到了支持作用。
Recent studies on proteins residing in the Golgi complex revealed that the membrane-spanning domain of these proteins are largely responsible for their retention in the Golgi complex. We show here that beta-1,4-galactosyltransferase (GT) forms homodimers and large oligomers in vivo, and the formation of the homodimers is dependent on cysteine and histidine residues within the transmembrane domain. Double mutations of these residues, Cys(29) --> Ser and His(32) --> Leu, abolish homodimerization and simultaneously reduce the Golgi retention. Co-immunoprecipitation of GT and various GT chimeras with anti-GT and anti-reporter molecule antibodies revealed that large aggregates of GT are associated with alpha- and beta-tubulins and also with other cellular proteins. This association between tubulins and GT suggests a supportive role of the cytoskeleton in the Golgi retention mechanism.