Cosson P, Schröder-Köhne S, Sweet D S, Démollière C, Hennecke S, Frigerio G, Letourneur F
Basel Institute for Immunology, Switzerland.
Eur J Cell Biol. 1997 Jun;73(2):93-7.
Sec20p and Tip20p were previously identified as two interacting proteins involved in early steps of the secretory pathway in Saccharomyces cerevisiae. Here we describe a novel temperature-sensitive allele of TIP20 and analyze its phenotype. While sec20 and tip20 mutants exhibited a defect in forward ER-to-Golgi transport at the non-permissive temperature, both were also defective for retrieval of various dilysine-tagged proteins from the Golgi back to the endoplasmic reticulum (ER) at lower temperature. Dilysine-dependent Golgi localization of Emp47p was also defective in both mutants. These results suggest a role for the Sec20/Tip20p complex in retrieval of dilysine-tagged proteins back to the ER.
Sec20p和Tip20p先前被鉴定为参与酿酒酵母分泌途径早期步骤的两种相互作用蛋白。在此，我们描述了TIP20的一个新的温度敏感等位基因，并分析了其表型。虽然sec20和tip20突变体在非允许温度下在前向内质网到高尔基体的转运中表现出缺陷，但在较低温度下，二者从高尔基体将各种双赖氨酸标记蛋白回收到内质网（ER）的过程中也存在缺陷。在这两种突变体中，Emp47p的双赖氨酸依赖性高尔基体定位也存在缺陷。这些结果表明Sec20/Tip20p复合物在将双赖氨酸标记蛋白回收到内质网的过程中发挥作用。
