mRNA Transport and Degradation in Eukaryotes

The process of moving messenger RNA (mRNA) from the nucleus to the cytoplasm, where protein synthesis occurs.

A type of RNA that is not translated into protein. It plays various roles in the cell, like regulating gene expression.

Proteins that help certain RNAs, like mRNA and ncRNA, get exported out of the nucleus.

Proteins embedded in the nuclear pore, where they bind to export adaptors and allow the RNA to leave the nucleus.

A set of proteins that regulate the stability of mRNA. These proteins can either protect the mRNA or mark it for degradation.

The process of breaking down mRNA into smaller pieces, preventing it from being translated into protein.

A mechanism where the poly-A tail of mRNA is shortened, which often leads to degradation of the mRNA.

The time it takes for half of the mRNA molecules in a cell to degrade.

A mechanism that ensures only properly processed mRNA leaves the nucleus, preventing errors in protein synthesis.

Nuclear pores are protein channels that allow the passage of molecules between the nucleus and cytoplasm. They are made up of nucleoporins, forming a complex structure called the nuclear pore complex (NPC).

A typical vertebrate somatic cell contains thousands of nuclear pores, each capable of facilitating hundreds of molecule translocations per second.

mRNA doesn't move freely through the nuclear pore. It passes through a mesh of hydrophobic FG-repeat nucleoporins, which act as a selective sieve.

The FG repeat nucleoporins form a brush-like structure inside the nuclear pore. This structure acts as a sieve, binding to specific proteins involved in nuclear export. This blocks the passage of large molecules while allowing smaller molecules to pass.

DBP5 is an RNA helicase that removes the nuclear export receptor TAP from mRNP once it reaches the cytoplasm. This unidirectional movement prevents mRNP from returning to the nucleus.

DBP5 joins the mRNA during transcription, but its activity to remove TAP is only activated once the mRNP reaches the cytoplasm.

mRNA export adaptors are transported back to the nucleus to prevent accumulation in the cytoplasm and allow further mRNA export.

The information encoded in mRNA determines the specific polypeptide synthesized and its frequency of translation.

Specific sequences or structures within an mRNA molecule that influence its stability. They can accelerate or slow down the rate of mRNA degradation, ultimately affecting protein production.

Sequences rich in adenine and uracil nucleotides found in the 3' untranslated region (3'UTR) of messenger RNA (mRNA). They act as destabilizing elements, promoting mRNA decay.

Proteins that bind to AU-rich elements (AREs) and facilitate their degradation. They act as recruiters for the cellular machinery responsible for breaking down mRNA.

A crucial element in mRNA stability regulation. The 3' untranslated region (3'UTR) contains regulatory sequences that influence the mRNA's lifespan.

A specialized cellular machinery that degrades aberrant or improperly processed RNA molecules. It acts as a quality control system for RNA, ensuring accurate protein synthesis.

A complex of proteins that targets aberrant RNA molecules to the exosome for degradation. It plays a crucial role in removing faulty RNA transcripts from the cell.

A large protein complex responsible for degrading RNA molecules in a 3'-to-5' direction. It is a key player in both normal RNA processing and the removal of aberrant RNA transcripts.

A cellular process that targets and degrades mRNAs containing premature termination codons (PTCs), which are mutations that result in truncated proteins considered harmful to the cell.

A type of mutation in mRNA that leads to the production of a truncated protein due to an early stop signal.

Proteins involved in the NMD pathway, recognizing and degrading PTC-containing mRNAs.

Special molecular structures located downstream of PTCs in mammalian cells. They mark the location where a premature stop codon is present.

RNAs containing a PTC are targeted for degradation by NMD due to their unusual 3' UTR features.

NMD targets mRNAs with extremely long regions at the end.

This event involves the removal of unwanted or damaged RNA sequences from the mRNA, leading to a more functional and stable mRNA.

This enzyme helps unwind the complex structures of RNA, making it easier for other proteins to read and process the genetic code.

The process of moving mRNA from its site of synthesis to a specific location within the cell, often for translation.

A type of mRNA localization where mRNA is uniformly distributed throughout the cell but is degraded except at the site of translation, ensuring translation only occurs at the desired location.

A type of mRNA localization where mRNA is initially free to diffuse but gets trapped at the site of translation, facilitated by interactions with specific proteins or structures.

A type of mRNA localization where mRNA is actively transported to its destination using motor proteins that move along cytoskeletal tracks within the cell.

Special sequences on mRNA that act as 'zip codes' directing it to specific locations in the cell.

Proteins that bind directly or indirectly to cis-elements on mRNA to link it to the correct motor protein for transport.

Proteins that prevent translation or trigger degradation of unlocalized mRNA, ensuring that only correctly localized mRNA is translated.

Specific structures or proteins at the destination location that bind to localized mRNA and hold it in place, anchoring the mRNA to the target site.

A specific type of regulation where translation is inhibited during mRNA transport. This ensures the translated protein is produced only at its target location, preventing wasteful protein synthesis.