Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne RNA Caps and Tails
Name: katie
Location: N/A
Country: N/A
Date: N/A


Question:
What are the possible biological roles of the cap and poly-A tail in mRNA?



Replies:
Katie,

Experiments have clearly shown that the poly-A tail on a mRNA is to prevent it from being dismantled in the cytosol of the cell by enzymes when it leaves the nucleus. RNAs without this tail are quickly dismantled and with the string of A's[as many as 200!], may last for 24 hours or more. The modified guanine nucleotide at the head of the messenger RNA [mRNA] identifies the molecules as a mRNA. It is a chemical signal as to what the molecule's function is to be. The other two types of RNA [ribosomal RNA(rRNA) and transfer RNA (tRNA)] appear to have chemical signaling to indicate their function as well. However, I must note that this chemical signaling has not be demonstrated conclusively as yet. Feb. 2000

Steve Sample



Click here to return to the Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory