TIP47 is not a component of lipid droplets
TIP47 is not a component of lipid droplets
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DOI：
10.1074/jbc.m102468200
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发表时间：
2001-06-29
影响因子：
4.8
通讯作者：
Pfeffer, SR
中科院分区：
文献类型：
--
作者：
Barbero, P;Buell, E;Pfeffer, SR
TIP47在体外和体内都能将甘露糖6-磷酸受体从内体运送到反式高尔基体网络，它直接和非常特异地结合到阳离子非依赖和阳离子依赖的甘露糖6-磷酸受体的细胞质结构域，TIP47与脂滴相关蛋白ADOPHLIN有43%的同源性；大部分同源性位于这些蛋白的N端附近。最近在本杂志上报道，在使用本实验室的抗血清进行的一项研究中，TIP47是脂滴(Wolins，N，E，Rubin，B，和Brasaemle，D.L，(2001)J，Biol Chem，278,5101-5108)的一种成分。我们在这里展示了Wolins等人的发现。很可能是由于我们的抗血清识别的HeLa细胞中的一种交叉反应，和/或我们的血清也与脂肪酶蛋白本身发生交叉反应，直接通过使用针对TIP47残基152-434残基的抗体在大肠杆菌中表达脂肪酶来显示，我表明TIP47不是脂滴的主要成分。
TIP47 functions in the delivery of mannose 6-phosphate receptors from endosomes to the trans-Golgi network both in vitro and in, vivo, It binds directly and very specifically to the cytoplasmic domains of both the cation-independent and cation-dependent mannose 6-phosphate receptors, TIP47 is 43% identical to a Lipid droplet-associated protein named adipophilin; much of the identity resides near the N termini of these proteins. It was recently reported in this journal, in a study using antiserum from this laboratory, that TIP47 is a constituent of lipid droplets (Wolins, N, E,, Rubin, B,, and Brasaemle, D. L, (2001) J, BioL Chem, 278, 5101-5108). We show here that the findings of Wolins et al. were likely due to either a cross-reactive, unidentified protein in HeLa cells that is recognized by our antiserum and/or the fact that our serum also cross-reacts with the adipophilin protein itself, shown directly by expression of adipophilin in Escherichia coli, Using antibodies specific for residues 152-434 of TIP47, me show that TIP47 is not st constituent of lipid droplets.