Download Mysterious Merlin and the Holy Grail

Mysterious Merlin and the Holy Grail
Lauren McCluskey
World-wide cancer is one of the leading causes of death; it is for this reason that the
regulation of cell survival is a fundamental aspect of modern biology. Cell growth is
regulated on many levels by different proteins. It is the malfunction of these proteins that can
lead to uncontrolled cell growth.
Genes produce proteins through transcription and translation via (messenger) mRNA
and RNA. Every gene is composed of a unique sequence of bases. There are four different
bases present in DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). The unique
base sequence corresponds to a unique sequence of mRNA and RNA.
Merlin is the protein product of the Nf2 gene. It is a classical tumour suppressing
protein, capable of restricting cell growth.
Proteins do not act alone; Merlin interacts with many other proteins within the cell.
Grail is a protein believed to function as a splice factor. Splice factors differentially cut
RNA to produce many variations (isoforms) of the same protein. The various isoforms may
have dramatically diverse functions. Grail is believed to splice Merlin to give an inactive
form with no tumour suppressing ability.
The aim of this project was to understand how Grail interacts with Merlin. The
presence of Grail in two cell types was examined using protein detection techniques.
Subsequently production of Grail was inhibited. The novel gene silencing technique RNA
interference was used to inhibit Grail.
In RNA interference small sections of bases identical in sequence to the target mRNA
are introduced into the cell. These small interfering units bind to the target mRNA. This is
recognised and degraded by the cell. Thus, no protein is made.
Theoretically silencing of Grail will allow over-expression of Merlin, due to the
absence of this ‘regulating factor.’ This uncontrolled expression of Merlin should lead to the
cessation of cell growth.
I did observed Grail expression in wild type cells. Unfortunately, I was unable to
silence the Grail gene. However, I nevertheless suspect that Grail is involved in the
alternative splicing of Merlin, and I am confident that evidence to support this will be eluded
in the near future.
Examensarbete i biologi 10p, University of Uppsala, spring 2003.
Department of Biology Education and Department of Evolutionary Biology, Uppsala University.
Supervisor: Beat Bornhauser