The BLOS1-interacting protein KXD1 is involved in the biogenesis of lysosome-related organelles

Traffic. 2012 Aug;13(8):1160-9. doi: 10.1111/j.1600-0854.2012.01375.x. Epub 2012 May 28.


Biogenesis of lysosome-related organelles (LROs) complex-1 (BLOC-1) is an eight-subunit complex involved in lysosomal trafficking. Interacting proteins of these subunits expand the understanding of its biological functions. With the implementation of the naïve Bayesian analysis, we found that a human uncharacterized 20 kDa coiled-coil KxDL protein, KXD1, is a BLOS1-interacting protein. In vitro binding assays confirmed the interaction between BLOS1 and KXD1. The mouse KXD1 homolog was widely expressed and absent in Kxd1 knockout (KO) mice. BLOS1 was apparently reduced in Kxd1-KO mice. Mild defects in the melanosomes of the retinal pigment epithelia and in the platelet dense granules of the Kxd1-KO mouse were observed, mimicking a mouse model of mild Hermansky-Pudlak syndrome that affects the biogenesis of LROs.

Publication types

  • Case Reports
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bayes Theorem
  • Blood Platelets / ultrastructure
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Disease Models, Animal
  • Genetic Testing
  • Hermanski-Pudlak Syndrome / etiology
  • Hermanski-Pudlak Syndrome / genetics
  • Humans
  • Lysosomes / metabolism
  • Mice
  • Mice, Knockout
  • Microscopy, Electron, Transmission
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / metabolism*
  • Protein Interaction Domains and Motifs / genetics
  • Retina / ultrastructure
  • Two-Hybrid System Techniques


  • BLOC1S1 protein, human
  • Carrier Proteins
  • KXD1 protein, human
  • Nerve Tissue Proteins