| First Author | Simpson F | Year | 2005 |
| Journal | Traffic | Volume | 6 |
| Issue | 6 | Pages | 442-58 |
| PubMed ID | 15882442 | Mgi Jnum | J:121601 |
| Mgi Id | MGI:3710717 | Doi | 10.1111/j.1600-0854.2005.00289.x |
| Citation | Simpson F, et al. (2005) A novel hook-related protein family and the characterization of hook-related protein 1. Traffic 6(6):442-58 |
| abstractText | The spatial organization of organelles within a cell is dependent on microtubules. Recently, members of the Hook family of proteins have been proposed to function in linking organelles to microtubules. We report the identification of a completely novel protein family, the Hook-related protein (HkRP) family, from which the Hook proteins have diverged. Bioinformatic analysis of the HkRP family revealed several conserved domains, including a unique C-terminal HkRP domain. The central region of each protein is comprised of an extensive coiled-coil domain, and the N-terminus contains a putative microtubule-binding domain. This domain has been shown to bind microtubules in the Hook protein and show that the HkRP1 protein is microtubule-associated. While endogenous HkRP1 has no distinct organelle association, expression of the C-terminal membrane-binding domain suggests a function of the HkRP1 in early endosome. Ultrastructural studies reveal that expression of the C-terminal HkRP1 domain causes an accumulation of internal membranes with an electron-dense coat. Co-localization studies show a concomitant redistribution of the early endosome marker sorting-nexin 1 but not the early endosome antigen-1 (EEA1). The steady-state distribution of the epidermal growth factor receptor is also specifically disrupted by expression of the C-terminal domain. We propose that HkRP1 is involved in the process of tubulation of sorting nexin-1 positive membranes from early endosome subdomains. |
