3.1 Papers
3.1.6 Chronological list
3.1.6.87 Eneqvist, T., Lundberg, E., Nilsson, L., Abagyan, R., Sauer-Eriksson, A.E.(2003). The transthyretin-related protein family. Eur. J. Biochem. 270(3):518-32
A number of proteins related to the homotetrameric transport protein
transthyretin (TTR) forms a highly conserved protein family, which we
present in an integrated analysis of data from different sources combined
with an initial biochemical characterization. Homologues of the
transthyretin-related protein (TRP) can be found in a wide range of species
including bacteria, plants and animals, whereas transthyretins have so far
only been identified in vertebrates. A multiple sequence alignment of 49
TRP sequences from 47 species to TTR suggests that the tertiary and
quaternary features of the three-dimensional structure are most likely
preserved. Interestingly, while some of the TRP orthologues show as little
as 30% identity, the residues at the putative ligand-binding site are
almost entirely conserved. RT/PCR analysis in Caenorhabditis elegans
confirms that one TRP gene is transcribed, spliced and predominantly
expressed in the worm, which suggests that at least one of the two
C. elegans TRP genes encodes a functional protein. We used double-stranded
RNA-mediated interference techniques in order to determine the
loss-of-function phenotype for the two TRP genes in C. elegans but detected
no apparent phenotype. The cloning and initial characterization of purified
TRP from Escherichia coli reveals that, while still forming a homotetramer,
this protein does not recognize thyroid hormones that are the natural
ligands of TTR. The ligand for TRP is not known; however, genomic data
support a functional role involving purine catabolism especially linked to
urate oxidase (uricase) activity.
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