Position: "Forskare" (UU)
Project: Structural studies on membrane proteins
Funding ends: 30 June, 2001
Background
The aim of the project is to determine the three dimensional
structure of a member of the Band 4.1 superfamily,
both with and without physiologically relevant ligands.
Proteins of this family are localised at the intracellular
side of the plasma membrane of animal cells. These
proteins are found in a number of cell adhesion structures
and are thought to connect the cytoskeleton to the
plasma membrane. Moreover, proteins of the Band 4.1
superfamily has recently been shown to be involved
in signal transduction pathways, indicating that these
proteins have complex functions involving both structural
and signalling properties. Determination of the three-dimensional
structure of members of this superfamily is important
for the understanding of their physiological function.
One of the most well studied proteins in the Band 4.1
superfamily is Ezrin. The amino terminal FERM domain
(FERM stands for the proteins Band 4.1, Ezrin, Radixin
and Moesin) of Ezrin has been shown to be localised
at the plasma membrane and has been shown to interact
with phosphatidylinositolphosphates with high affinity.
Furthermore, Ezrin interacts with the intracellular
portion of the transmembrane proteins ICAM1, ICAM2,
ICAM3 and CD44.
Present work
The cDNA coding for the FERM domain of Ezrin was cloned
into a bacterial expression vector. The FERM domain
is expressed as a glutathione S-transferase (GST) fusion
protein that allows efficient purification of the protein
using glutathione sepharose. Major efforts are now
focused on finding conditions that can promote the
formation of protein crystals.
During year 2000 another group published the structure
of the FERM domain of Radixin. The sequence of this
molecule is almost to identical to Ezrin and therefore
professor Alwyn Jones and I decided not to continue
our attempts to solve the structure of the FERM domain
of Ezrin. Alternative projects focused on functional
studies of FERM domains have been considered. However,
we are running out of funding and it is unclear if
these new projects can be realised.
Latest update at 5 March, 2001.