Faculty Collaboration Database

Neuron-specific specificity protein 4 bigenomically regulates the transcription of all mitochondria- and nucleus-encoded cytochrome c oxidase subunit genes in neurons. J Neurochem 2013 Nov;127(4):496-508

Date

09/17/2013

Pubmed ID

24032355

Pubmed Central ID

PMC3820366

DOI

10.1111/jnc.12433

Scopus ID

2-s2.0-84887119851 (requires institutional sign-in at Scopus site)   25 Citations

Abstract

Neurons are highly dependent on oxidative metabolism for their energy supply, and cytochrome c oxidase (COX) is a key energy-generating enzyme in the mitochondria. A unique feature of COX is that it is one of only four proteins in mammalian cells that are bigenomically regulated. Of its thirteen subunits, three are encoded in the mitochondrial genome and ten are nuclear-encoded on nine different chromosomes. The mechanism of regulating this multisubunit, bigenomic enzyme poses a distinct challenge. In recent years, we found that nuclear respiratory factors 1 and 2 (NRF-1 and NRF-2) mediate such bigenomic coordination. The latest candidate is the specificity factor (Sp) family of proteins. In N2a cells, we found that Sp1 regulates all 13 COX subunits. However, we discovered recently that in primary neurons, it is Sp4 and not Sp1 that regulates some of the key glutamatergic receptor subunit genes. The question naturally arises as to the role of Sp4 in regulating COX in primary neurons. The present study utilized multiple approaches, including chromatin immunoprecipitation, promoter mutational analysis, knockdown and over-expression of Sp4, as well as functional assays to document that Sp4 indeed functionally regulate all 13 subunits of COX as well as mitochondrial transcription factors A and B. The present study discovered that among the specificity family of transcription factors, it is the less known neuron-specific Sp4 that regulates the expression of all 13 subunits of mitochondrial cytochrome c oxidase (COX) enzyme in primary neurons. Sp4 also regulates the three mitochondrial transcription factors (TFAM, TFB1M, and TFB2M) and a COX assembly protein SURF-1 in primary neurons.

Author List

Johar K, Priya A, Dhar S, Liu Q, Wong-Riley MT

MESH terms used to index this publication - Major topics in bold

Animals
Cell Line, Tumor
Cell Nucleus
Cells, Cultured
DNA-Binding Proteins
Electron Transport Complex IV
Female
Gene Knockdown Techniques
Genome, Mitochondrial
High Mobility Group Proteins
Male
Mice
Mice, Inbred C57BL
Neurons
Protein Binding
Protein Subunits
Sp4 Transcription Factor
Transcription Factors
Transcription, Genetic
Visual Cortex