Final answer:
Control mechanisms for the cellular distribution of mRNAs include RNA stability, translational control, and the actions of RNA binding proteins and microRNAs.
Step-by-step explanation:
The cellular distribution of mRNAs can be controlled through several mechanisms:
- RNA stability: The longer an mRNA exists in the cytoplasm, the more time it has to be translated into protein. Factors such as the length of the poly-A tail can contribute to mRNA stability.
- Translational control: Translation of mRNA into protein can be regulated at various levels. For example, in proteins destined for the endoplasmic reticulum, a signal recognition particle (SRP) binds to a specific sequence in the mRNA, halting translation until the mRNA-ribosome complex reaches the endoplasmic reticulum.
- RNA binding proteins and microRNAs: RNA stability can be altered by RNA-binding proteins (RPBs) and microRNAs (miRNAs). These molecules can bind to specific regions of the mRNA, either increasing or decreasing its stability and affecting protein synthesis.