Xin Jie Chen, Ph.D. Associate Professor, Biochemistry and Molecular Biology 4262 Weiskotten Hall Upstate Medical University 750 East Adams Street Syracuse, NY 13210 (315) 464-8723

Education and Clinical Training

Research Program and Department Affiliations

Research Interests

Research Abstract

Mitochondria are the powerhouses that generate energy by oxidative phosphorylation (OXPHOS) to support cellular activities. Mitochondria also receive and emit cellular signals to promote cell death. The biology of mitochondria is fascinating. Structurally, mitochondria are sub-compartmentalized into the outer and inner membranes, matrix and the inter-membrane space. Specific molecular machineries are required for targeting the proteins to correct locations, and for maintaining them in the right conformations in order to fulfill their functions. Genetically, the operation of the OXPHOS apparatus requires a coordinated expression of genes from two physically separated genomes: the mitochondrial genome which encodes integral components of the OXPHOS pathway, and the nuclear genome that directly contributes to OXPHOS as well as takes care of the mitochondrial genome for its replication, transcription, transmission and other mtDNA transactions. Effective nuclear-mitochondrial communication is therefore critical for maintaining mitochondrial activity. Functionally, mitochondria are intricate organelles that can switch from a life-supporting apparatus into a death-executing machinery, through the integration of intrinsic and extrinsic cellular signals.

Mitochondria are also the “powerhouses of diseases”. Mitochondrial dysfunction is associated with a rapidly increasing number of aging-related neuromuscular degenerative diseases, metabolic disorders and tumorigenesis.

Finally, mitochondrial dysfunction is also believed to contribute to aging, but the underlying mechanism is not well understood.

The ongoing research in our laboratory is focused on the following projects:

(1) We are interested to understand how the mitochondrial system degenerates during aging and contributes to aging-related diseases. Our ultimate goal is to identify evolutionarily conserved cellular pathways that can potentially delay and possibly, reverse the degenerative process.

(2) We investigate the mechanisms of mitochondrial DNA (mtDNA) organization and inheritance. Elucidating these fundamental processes could help to better understand the pathogenesis of a variety of human diseases involving mtDNA disintegration.

(3) We study the structure, function, and regulation of the newly identified calcium-dependent mitochondrial carriers, as represented by Sal1p, which couples cytosolic calcium-signaling with mitochondrial function.

Selected publications:

Wang X, Zuo X, Kucejova B and Chen XJ. Reduced cytosolic protein synthesis suppresses mitochondrial degeneration (2008) Nat Cell Biol. 10:1090-7.

Wang X, Salinas K, Zuo X, Kucejova B and Chen XJ. (2008) Dominant membrane uncoupling by mutant adenine nucleotide translocase in mitochondrial diseases. Hum Mol Genet. 17:4036-44.

Kucej M, Kucejova B, Subramanian R, Chen XJ and Butow RA (2008). Mitochondrial nucleoids undergo remodeling in response to metabolic cues. J Cell Sci. 121:1861-8.

Kucejova B, Li L, Wang X, Giannattasio S and Chen XJ (2008) Pleiotropic effects of the yeast Sal1 and Aac2 carriers on mitochondrial function via an activity distinct from adenine nucleotide transport. Mol Genet Genomics. 280:25-39.

Chen XJ*, Wang X, Butow RA* (*co-corresponding authors) (2007) Yeast aconitase binds and provides metabolically coupled protection to mitochondrial DNA. Proc Natl Acad Sci U S A. 104:13738-43.

Chen XJ and Butow RA (2005) Organization and inheritance of mitochondrial nucleoids. Nature Review Genetics 6:815-825.

Chen XJ Wang XW, Kaufman, BA and Butow RA (2005) Aconitase couples metabolic regulation to mitochondrial DNA maintenance. Science 307:714-717.

Chen XJ (2004) Sal1p, a calcium-dependent carrier protein that suppresses an essential cellular function associated with the Aac2p isoform of ADP/ATP translocase in Saccharomyces cerevisiae. Genetics 167:607-617.

Chen XJ (2002) Induction of an unregulated channel by mutant nucleotide translocase suggests an explanation for human ophthalmoplegia. Human Molecular Genetics 16: 1835-1843.

Zuo XM, Clark-Walker GD and Chen XJ (2002). The mitochondrial nucleoid protein, Mgm101p, of Saccharomyces cerevisiae is involved in the maintenance of r⁺ and ori/rep-devoid petite genomes but is not required for hypersuppressive r^- mtDNA. Genetics 160:1389-1400.

Clark-Walker GD and Chen XJ (2001) Dual mutations reveal interactions between components of oxidative phosphorylation in Kluyveromyces lactis. Genetics 159, 929-938.

Publications - link to PubMed

This profile was last updated on 10/16/2009

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