Kragler Friedrich, Curin Mirela, Trutnyeva Kateryna, Gansch Andreas, Waigmann Elisabeth
Max F. Perutz Laboratories, University Departments at the Vienna Biocenter, Institute of Medical Biochemistry, University of Vienna, Dr. Bohr-Gasse. 9, A-1030 Vienna, Austria.
Plant Physiol. 2003 Aug;132(4):1870-83. doi: 10.1104/pp.103.022269.
The movement protein of tobacco mosaic virus, MP30, mediates viral cell-to-cell transport via plasmodesmata. The complex MP30 intra- and intercellular distribution pattern includes localization to the endoplasmic reticulum, cytoplasmic bodies, microtubules, and plasmodesmata and likely requires interaction with plant endogenous factors. We have identified and analyzed an MP30-interacting protein, MPB2C, from the host plant Nicotiana tabacum. MPB2C constitutes a previously uncharacterized microtubule-associated protein that binds to and colocalizes with MP30 at microtubules. In vivo studies indicate that MPB2C mediates accumulation of MP30 at microtubules and interferes with MP30 cell-to-cell movement. In contrast, intercellular transport of a functionally enhanced MP30 mutant, which does not accumulate and colocalize with MP30 at microtubules, is not impaired by MPB2C. Together, these data support the concept that MPB2C is not required for MP30 cell-to-cell movement but may act as a negative effector of MP30 cell-to-cell transport activity.
烟草花叶病毒的运动蛋白MP30通过胞间连丝介导病毒的细胞间转运。MP30复杂的细胞内和细胞间分布模式包括定位于内质网、细胞质体、微管和胞间连丝，并且可能需要与植物内源因子相互作用。我们从寄主植物烟草中鉴定并分析了一种与MP30相互作用的蛋白MPB2C。MPB2C是一种以前未被表征的微管相关蛋白，它在微管上与MP30结合并共定位。体内研究表明，MPB2C介导MP30在微管上的积累，并干扰MP30的细胞间运动。相比之下，一种功能增强的MP30突变体在微管上不积累也不与MP30共定位，其细胞间转运不受MPB2C的影响。这些数据共同支持了这样一种概念，即MPB2C不是MP30细胞间运动所必需的，但可能作为MP30细胞间转运活性的负效应物发挥作用。
