Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Electrical stimulation of neonatal cardiac myocytes produces hypertrophy and cellular maturation with increased mitochondrial content and activity. To investigate the patterns of gene expression associated with these processes, cardiac myocytes were stimulated for varying times up to 72 hr in serum-free culture. The mRNA contents for genes associated with transcriptional activation [c-fos, c-jun, JunB, nuclear respiratory factor 1 (NRF-1)], mitochondrial proliferation [cytochrome c (Cyt c), cytochrome oxidase], and mitochondrial differentiation [carnitine palmitoyltransferase I (CPT-I) isoforms] were measured. The results establish a temporal pattern of mRNA induction beginning with c-fos (0.25-3 hr) and followed sequentially by c-jun (0.5-3 hr), JunB (0.5-6 hr), NRF-1 (1-12 hr), Cyt c (12-72 hr), and muscle-specific CPT-I (48-72 hr). Induction of the latter was accompanied by a marked decrease in the liver-specific CPT-I mRNA, thus supporting the developmental fidelity of this pattern of gene regulation. Consistent with a transcriptional mechanism, electrical stimulation increased c-fos, beta-myosin heavy chain, and Cyt c promoter activities. These increases coincided with a rise in their respective endogenous gene transcripts. NRF-1, cAMP response element, and Sp-1 site mutations within the Cyt c promoter reduced luciferase expression in both stimulated and nonstimulated myocytes. Mutations in the NRF-1 and CRE sites inhibited the induction by electrical stimulation (5-fold and 2-fold, respectively) whereas mutation of the Sp-1 site maintained or increased the fold induction. This finding is consistent with the appearance of NRF-1 and fos/jun mRNAs prior to that of Cyt c and suggests that induction of these transcription factors is a prerequisite for the transcriptional activation of Cyt c expression. These results support a regulatory role for NRF-1 and possibly AP-1 in the initiation of mitochondrial proliferation.
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PMID:Electrical stimulation of neonatal cardiomyocytes results in the sequential activation of nuclear genes governing mitochondrial proliferation and differentiation. 932 21

Nitric oxide (NO) is a mobile, highly reactive signal molecule, and changes the expression of specific genes in effector cells. Under physiological conditions, NO reacts with molecular oxygen and with reactive oxygen species (ROS) to produce intermediates known as reactive nitrogen species (RNS). The production of NO and RNS in the cell is controlled by hormones, neurotransmitters, cytokines, and growth factors. Hence NO and its derivatives act as secondary paracrinous factors and transmit the signal from NO-producing to neighboring cells. Intracellular reception of NO and RNS is due to Src-related tyrosine protein kinases, G-protein Ras, cytochrome oxidase, and guanylate cyclase. Receptor proteins mostly contain heme, active thiol, or iron-sulfur groups, and are both on the plasma membrane and in internal cell compartments. Many of the NO receptors are the key components of cell regulatory systems controlling the transcription factors AP-1, HIF-1, NF-kappa B, and p53 and the expression of their target genes. A distinguishing feature of NO signaling is that changes in redox potential of the cell switch the NO receptor and, consequently, modify the NO effect. Depending on the ROS level, NO activates different signal transduction pathways to induce (or suppress) different gene sets. The data considered indicate that antioxidants may be used to directionally change the transcriptional response of the cell to NO.
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PMID:[Redox-dependent regulation of gene expression induced by nitric oxide]. 1504 36