mitochondrial transcription

Definition

Target type: biologicalprocess

The synthesis of RNA from a mitochondrial DNA template, usually by a specific mitochondrial RNA polymerase. [GOC:jl, PMID:23632312]

Mitochondrial transcription is a complex process that occurs within the mitochondria, the powerhouses of the cell. Unlike nuclear transcription, which relies on a single RNA polymerase, mitochondrial transcription utilizes a specialized RNA polymerase known as mitochondrial RNA polymerase (POLRMT). The process begins with the recognition and binding of POLRMT to specific promoter sequences located on the mitochondrial DNA (mtDNA). These promoters, which are typically located upstream of the genes they regulate, serve as initiation sites for transcription. Once bound to the promoter, POLRMT unwinds the DNA double helix, creating a template strand for transcription.

RNA polymerase then uses ribonucleoside triphosphates (NTPs) as building blocks to synthesize a complementary RNA molecule, following the base pairing rules: adenine (A) with uracil (U), guanine (G) with cytosine (C). The newly synthesized RNA transcript, called mitochondrial RNA (mtRNA), is a single-stranded molecule that is complementary to the DNA template strand.

Mitochondrial transcription is a highly regulated process that is influenced by various factors, including the availability of transcription factors, the cellular energy status, and the presence of specific signaling molecules. These regulatory mechanisms ensure that mitochondrial gene expression is tightly controlled to meet the cell's energy demands.

Upon completion of transcription, mtRNA undergoes processing steps, such as splicing and polyadenylation, to produce functional mitochondrial transcripts. These transcripts include messenger RNAs (mRNAs) that encode proteins involved in oxidative phosphorylation, ribosomal RNAs (rRNAs) that form the core of mitochondrial ribosomes, and transfer RNAs (tRNAs) that carry amino acids to the ribosomes during protein synthesis.'
"

Proteins (2)

Compounds (2)