Mar 2023
Abstract:
In contrast to
early understanding, both the meaning of individual codons (genetic
'words') and the framing of the readout process can be modified by
information in specific mRNAs or its encoded product. Such 'recoding' is
distinct from context-independent departures in certain specialized
niches, e.g. certain mitochondria, from the otherwise universal genetic
code. Some occurrences of recoding serve regulatory or quality control
purposes whereas others serve to yield an extra product from a single
gene in a set ratio to the product of standard decoding. Recoding is
prevalent in viral decoding, especially of RNA viruses, but is also
frequent in mobile element gene expression. With a very few exceptions,
recoding is much less common in chromosomal gene expression, though
nevertheless important e.g. in the instance conserved from yeast to
humans. Efforts to synthetically manipulate recoding for human benefit
will be addressed.
Bio:
John F.
Atkins was born in Ireland and obtained both his primary and Ph.D
degrees in genetics from Trinity College Dublin. When type 2 restriction
enzymes first became available in Cold Spring Harbor Lab. he helped
develop a protein coding gene mapping technique and its application to
adenovirus. Separately as a major company employee, he initiated a
scheme for transofmation of yeast with an endogenous plasmid. However,
starting from the time that decoding was thought to be invariably and
immutably triplet, his main work in Ireland and the University of Utah
has been on discoveries of several types of reprogramming during genetic
readout -recoding. Identification of ribosomal access to new frame
'hidden' information has expanded knowledge of viral products.
Regulatory frameshifting conserved from yeast to humans has been
revealed together with identification of the enabling mechanistic
signals including those required by the causative virus of Covid-19.
Several types of dynamic redefinition of codón meaning, including a
special case in neuronal cells, and in the decoding of one coding
sequence where 132 UGA codons specify the 21st amino acid
selenocysteine. JFA was the first Life sciences Director of Science
Foundation Ireland and is a gold medallist of the Royal Irish Academy.