Our major interests are in subcellular targeting, translocation across membranes, folding and subcellular distribution of proteins in yeast as a model for eukaryotic cells and human disease. For more than fifteen years our work has focused on dual targeting of proteins in eukaryotes and in particular situations in which single translation products are distributed between mitochondria and a second subcellular location. To this end we have developed bioinformatic and proteomic screens for dual localization. Remarkably, we estimate that in yeast a third of the mitochondrial proteome is dual localized. This research has revealed novel phenomena such as “reverse translocation” across mitochondrial membranes, “translation coupled import” into mitochondria and “eclipsed distribution” of proteins in eukaryotes.
The following are a number of topics under our investigation in Singapore and Israel which are related to human metabolic and inflammatory diseases:
Hsp60 has been shown to be involved in inflammatory disease. By examining Hsp60 expression in yeast we have discovered that cytosolic Hsp60 can modulate proteasome proteolytic activity. The physiological conditions for release or expression of Hsp60 in yeast and the human cell cytosol are the aim of our current experiments.
The enzyme fumarase and its metabolite fumarate have been implicated in kidney cancer we have shown that it is involved in the cellular response to DNA damage. The team is in the process of developing approaches to determine the precise stage at which fumarase participates in DNA damage signaling.
Dual targeting of mitochondrial aconitase is a paradigm of reverse translocation and eclipsed distribution. The aim of our current research is to identify signal(s) of this dual distribution. The amino terminal domain appears to be an independent element of dual targeting.
Project: DNA Damage/DNA damage sensing and the initiation of inflammatory processes linked to malignant disease
Regev-Rudzki N, Battat E, Goldberg I, and Pines O. 2009. Dual localization of fumarase is dependent on the integrity of the glyoxylate shunt. Mol. Microbiol. 72: 297-306. Commentry on this paper entitled: "Putting a break on protein translocation: metabolic regulation of mitochondrial protein import" by J. Herrmann was published in the same issue.
Spiegel R, Shaag A, Edvardson S, Mandel H, Stepensky P, Shalev S, Pines O, Elpeleg O. 2009. Bilateral striatal necrosis and polyneuropathy in childhood, due to mutation in the SLC25A19 gene, is allelic to the Amish congenital microcephaly Ann. Neurol., 66: 419-424.
Naamati A, Regev-Rudzki N, Galperin S, Lill R and Pines O. 2009. Dual targeting of Nfs1 and discovery of its novel processing enzyme, Icp55. J. Biol. Chem., 284: 30200-8.
Eliyahu E, Pnueli L, Melamed D, Scherrer T, Gerber AP, Pines O, Rapaport D and Arava Y. 2010. Tom20 mediates localization of mRNAs to mitochondria in a translation-dependent manner. Mol. Cell Biol. 30: 284-94.
Matthews DG, Gur N, Koopman WJH, Pines O and Vardimon L. 2010. Weak mitochondrial targeting sequence determines tissue-specific subcellular localization of glutamine synthetase in liver and brain cells. J. Cell Sci. 123: 351-9.
Yogev O, Yogev O, Shay E, Shaulian E, Goldberg M, Fox TD, and Pines O. 2010. Fumarase: a mitochondrial metabolic enzyme and a cytosolic/nuclear component of the DNA damage response. PLoS Biol. 8 (3):e1000328.
Yogev O and Pines O. 2010. Dual targeting of mitochondrial proteins: Mechanism, regulation and function. BBA – Biomembranes. 1808: 1012-20.
Kaufmann R, Straussberg R, Mandel H, Fattal-Valevski A, Ben-Zeev B, Naamati A, Shaag A, Zenvirt S, Konen O, Mimuni-Bloch A, Dobyns WB, Pines O, Elpeleg O. 2010. Infantile cerebral and cerebellar atrophy is associated with a mutation in the MED17 subunit of the transcription preinitiation Mediator complex. Am. J. Hum. Genet. 87:667-70.
Ben-Menachem R, Regev-Rudzki N, Pines O. 2011. The aconitase C-terminal domain is an independent dual targeting element. J. Mol. Biol. 409: 113-23.
Ben-Menachem R, Tal M, Shadur T and Pines O. 2011. A third of the yeast mitochondrial proteome is dual localized: a question of evolution. Proteomics. 11: 4468-76.
Yogev O, Naamati A and Pines O. 2011. Dual localization of fumarase and the role of cytosolic fumarase in the DNA damage response. Invited review, FEBS Journal. 278: 4230-42.
Mühlenhoff U, Richter N, Pines O, Pierik AJ, and Lill R. 2011. Specialized function of yeast Isa1 and Isa2 in the maturation of mitochondrial [4FE-4S] proteins. J. Biol. Chem. 286: 41205-16.