A splice variant of RILP induces lysosomal clustering independent of dynein recruitment

Biochem Biophys Res Commun. 2006 Jun 9;344(3):747-56. doi: 10.1016/j.bbrc.2006.03.178. Epub 2006 Apr 6.

Abstract

The small GTPase Rab7 controls fusion and transport of late endocytic compartments. A critical mediator is the Rab7 effector RILP that recruits the minus-end dynein-dynactin motor complex to these compartments. We identified a natural occurring splice variant of RILP (RILPsv) lacking only 27 amino acids encoded by exon VII. Both variants bind Rab7, prolong its GTP-bound state, and induce clustering of late endocytic compartments. However, RILPsv does not recruit the dynein-dynactin complex, implicating exon VII in motor recruitment. Clustering might still occur via dimerization, since both RILP and RILPsv are able to form hetero- and homo-dimers. Moreover, both effectors compete for Rab7 binding but with different outcome for dynein-dynactin recruitment and transport. Hence, RILPsv provides an extra dimension to the control of vesicle fusion and transport by the small GTPase Rab7.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Binding Sites
  • Carrier Proteins / metabolism*
  • Cell Line, Tumor
  • Dyneins / metabolism*
  • Endocytosis*
  • Genetic Variation / genetics
  • Humans
  • Lysosomes / metabolism*
  • Lysosomes / ultrastructure*
  • Melanoma / metabolism*
  • Melanoma / ultrastructure
  • Molecular Motor Proteins / metabolism*
  • Molecular Motor Proteins / ultrastructure
  • Protein Binding
  • Protein Splicing / genetics
  • Structure-Activity Relationship
  • rab GTP-Binding Proteins / metabolism
  • rab7 GTP-Binding Proteins

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Molecular Motor Proteins
  • RILP protein, human
  • rab7 GTP-Binding Proteins
  • rab7 GTP-binding proteins, human
  • Dyneins
  • rab GTP-Binding Proteins