Cellular and Molecular Life Sciences

, Volume 66, Issue 17, pp 2897–2911

HIP1 exhibits an early recruitment and a late stage function in the maturation of coated pits

Research Article

DOI: 10.1007/s00018-009-0077-4

Cite this article as:
Gottfried, I., Ehrlich, M. & Ashery, U. Cell. Mol. Life Sci. (2009) 66: 2897. doi:10.1007/s00018-009-0077-4

Abstract

Huntingtin interacting protein 1 (HIP1) is an accessory protein of the clathrin-mediated endocytosis (CME) pathway, yet its precise role and the step at which it becomes involved are unclear. We employed live-cell imaging techniques to focus on the early steps of CME and characterize HIP1 dynamics. We show that HIP1 is highly colocalized with clathrin at the plasma membrane and shares similar dynamics with a subpopulation of clathrin assemblies. Employing transferrin receptor fused to pHluorin, we distinguished between open pits to which HIP1 localizes and newly internalized vesicles that are devoid of HIP1. Moreover, shRNA knockdown of clathrin compromised HIP1 membranal localization, unlike the reported behavior of Sla2p. HIP1 fragment, lacking its ANTH and Talin-like domains, inhibits internalization of transferrin, but retains colocalization with membranal clathrin assemblies. These data demonstrate HIP1’s role in pits maturation and formation of the coated vesicle, and its strong dependence on clathrin for membranal localization.

Keywords

HIP1 Clathrin Endocytosis TIRF Live-cell imaging 

Supplementary material

18_2009_77_MOESM1_ESM.tif (651 kb)
HIP1218-604 localizes to small dynamic assemblies at the PM, colocalized with clathrin. A. An example of a short-lived (32 s) HIP1218-604 assembly (box). B. Filtered TIRF images of part of a cell coexpressing HIP1218-604-EGFP and tdTomato-CLC. Merged image demonstrates the high colocalization of the two proteins (HIP1218-604 in green, clathrin in red). (TIFF 651 kb)

Copyright information

© Birkhäuser Verlag, Basel/Switzerland 2009

Authors and Affiliations

  1. 1.Department of Neurobiology, The George S. Wise Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael
  2. 2.Department of Cell Research and Immunology, Faculty of Life SciencesTel Aviv UniversityTel AvivIsrael

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