Section of Surgical Sciences and Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
Mol Biol Cell. 2013 Mar;24(5):643-58. doi: 10.1091/mbc.E12-09-0659. Epub 2013 Jan 2.
The Rab11-family interacting proteins (Rab11-FIPs) facilitate Rab11-dependent vesicle recycling. We hypothesized that Rab11-FIPs define discrete subdomains and carry out temporally distinct roles within the recycling system. We used live-cell deconvolution microscopy of HeLa cells expressing chimeric fluorescent Rab11-FIPs to examine Rab11-FIP localization, transferrin passage through Rab11-FIP-containing compartments, and overlap among Rab11-FIPs within the recycling system. FIP1A, FIP2, and FIP5 occupy widely distributed mobile tubules and vesicles, whereas FIP1B, FIP1C, and FIP3 localize to perinuclear tubules. Internalized transferrin entered Rab11-FIP-containing compartments within 5 min, reaching maximum colocalization with FIP1B and FIP2 early in the time course, whereas localization with FIP1A, FIP1C, FIP3, and FIP5 was delayed until 10 min or later. Whereas direct interactions with FIP1A were only observed for FIP1B and FIP1C, FIP1A also associated with membranes containing FIP3. Live-cell dual-expression studies of Rab11-FIPs revealed the tubular dynamics of Rab11-FIP-containing compartments and demonstrated a series of selective associations among Rab11-FIPs in real time. These findings suggest that Rab11-FIP1 proteins participate in spatially and temporally distinct steps of the recycling process along a complex and dynamic tubular network in which Rab11-FIPs occupy discrete domains.
Rab11 家族相互作用蛋白 (Rab11-FIPs) 促进 Rab11 依赖性囊泡再循环。我们假设 Rab11-FIPs 定义了离散的亚域，并在再循环系统中执行时间上不同的作用。我们使用表达嵌合荧光 Rab11-FIP 的 HeLa 细胞的活细胞反卷积显微镜检查 Rab11-FIP 定位、转铁蛋白通过包含 Rab11-FIP 的隔室的传递以及再循环系统中 Rab11-FIP 之间的重叠。FIP1A、FIP2 和 FIP5 占据广泛分布的移动小管和囊泡，而 FIP1B、FIP1C 和 FIP3 定位于核周小管。内化的转铁蛋白在 5 分钟内进入包含 Rab11-FIP 的隔室，在时间过程的早期与 FIP1B 和 FIP2 最大程度地共定位，而与 FIP1A、FIP1C、FIP3 和 FIP5 的定位则延迟到 10 分钟或更晚。虽然仅观察到 FIP1A 与 FIP1B 和 FIP1C 的直接相互作用，但 FIP1A 也与包含 FIP3 的膜结合。Rab11-FIP 的活细胞双表达研究揭示了包含 Rab11-FIP 的隔室的管状动力学，并实时证明了 Rab11-FIP 之间的一系列选择性关联。这些发现表明，Rab11-FIP1 蛋白参与了再循环过程中沿复杂动态管状网络的空间和时间上不同的步骤，其中 Rab11-FIPs 占据离散的域。
