Kinectin Anchors the Translation Elongation Factor-1δ to the Endoplasmic Reticulum

• DOI: 10.1074/jbc.m210917200
• Publication Date: 2003-08-15T20:14:13Z
• Authors: Lee-Lee Ong; Connie P.N. Er; Andrea Ho; May T. Aung; Hanry Yu
• Keywords: 0301 basic medicine; 03 medical and health sciences; Peptide Elongation Factor 1; Two-Hybrid System Techniques; Membrane Proteins; 540; Endoplasmic Reticulum; Protein Binding

Kinectin has been proposed to be a membrane anchor for kinesin on intracellular organelles. A kinectin isoform that lacks a major portion of the kinesin-binding domain does not bind kinesin but interacts with another resident of the endoplasmic reticulum, the translation elongation factor-1 delta (EF-1 delta). This was shown by yeast two-hybrid analysis and a number of in vitro and in vivo assays. EF-1 delta provides the guanine nucleotide exchange activities on EF-1 alpha during elongation step of protein synthesis. The minimal EF-1 delta-binding domain on kinectin resides within a conserved region present in all the kinectin isoforms. Overexpression of the kinectin fragments in vivo disrupted the intracellular localization of EF-1 delta proteins. This report provides evidence of an alternative kinectin function as the membrane anchor for EF-1 delta on the endoplasmic reticulum and provides clues to the EF-1 complex assembly and anchorage on the endoplasmic reticulum.