In Vitro Cellular & Developmental Biology - Animal

, Volume 38, Issue 10, pp 582–594

Novel complex integrating mitochondria and the microtubular cytoskeleton with chromosome remodeling and tumor suppressor rassf1 deduced by in silico homology analysis, interaction cloning in yeast, and colocalization in cultured cells

  • Leyuan Liu
  • Amy Vo
  • Guoqin Liu
  • Wallace L. McKeehan
Articles Cell Growth/Differentiation/Apoptosis

DOI: 10.1290/1543-706X(2002)38<582:NCIMAT>2.0.CO;2

Cite this article as:
Liu, L., Vo, A., Liu, G. et al. In Vitro Cell.Dev.Biol.-Animal (2002) 38: 582. doi:10.1290/1543-706X(2002)38<582:NCIMAT>2.0.CO;2

Summary

Availability of the complete sequence of the human genome and sequence homology analysis has accelerated new protein discovery and clues to protein function. Protein-protein interaction cloning suggests multisubunit complexes and pathways. Here, we combine, these molecular approaches with cultured cell colocalization analysis to suggest a novel complex and a pathway that integrate the mitochondrial location and the microtubular cytoskeleton, with chromosome remodeling apoptosis, and tumor suppression based on a novel leucine-rich pentatricopeptide repeat-motif-containing protein (LRPPRC) that copurified with the fibroblast growth factor receptor complex. One round of interaction cloning and sequence homology analysis defined a primary LRPPRC complex with novel subunits cat eye syndrome chromosome region candidate 2 (CECR2), ubiquitously expressed transcript (UXT), and chromosome 19 open reading frames 5 (C19ORF5) but still of unknown function. Immuno, deoxyribonucleic acid (DNA), and green fluorescent protein (GFP) tag colocalization analyses revealed that LRPPRC appears in both cytosol and nuclei of cultured cells, colocalizes with mitochondria and β-tubulin rather than with α-actin in the cytosol of interphase cells, and exhibits phase-dependent organization around separating chromosomes in mitotic cells. GFP-tagged CECR2B was strictly nuclear and colocalized with condensed DNA in apoptotic cells. GFP-tagged UXT and GFP-tagged C19ORF5 appeared in both cytosol and nuclei and colocalized with LRPPRC and β-tubulin. Cells, exhibiting nuclear C19ORF5 were apoptotic. Screening for interactive substrates with the primary LRPPRC substrates in the human liver complementary DNA library revealed that CECR2B interacted with chromatin-associated TFIID-associated protein TAFII30 and ribonucleic acid splicing factor SRP40, UXT bridged to CBP/p300-binding factor CITED2 and kinetochore-associated factor BUB3, and C19ORF5 complexed with mitochondria-associated NADH dehydrogenase I and cytochrome c oxidase I. C19ORF5 also interacted with RASSF1, providing a bridge to apoptosis and tumor suppression.

Key words

apoptosis chromosome separation cytokinesis genetic instability microtubule-associated proteins nucleo-cytosolic shuttling tumor suppressor 

Copyright information

© Society for In Vitro Biology 2002

Authors and Affiliations

  • Leyuan Liu
    • 1
  • Amy Vo
    • 1
  • Guoqin Liu
    • 2
  • Wallace L. McKeehan
    • 1
  1. 1.Center for Cancer Biology and Nutrition, Institute of Biosciences and TechnologyTexas A&M University System Health Science CenterHouston
  2. 2.State Key Laboratory of Plant Physiology and Biochemistry, College of Biological SciencesChina Agricultural UniversityBeijingP.R. China

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