The plasma protein fetuin: common structural features of the mammalian fetuin family

Brown, William Michael (1991) The plasma protein fetuin: common structural features of the mammalian fetuin family University of Southampton, Department of Clinical Neurological Sciences, Doctoral Thesis , 222pp.


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The structure and tissue-specific expression of the bovine
plasma glycoprotein fetuin and its homologues in other species has
been examined. From the known partial amino acid sequence of bovine
fetuin, degenerate oligonucleotide probes were designed. These
probes were end-labelled using 14 polynucleotide kinase and were
used to screen an adult bovine liver cDNA library by plaque
hybridisation. A cDNA encoding the whole of the plasma protein was
obtained and was fully sequenced on both strands. The deduced amino
acid sequence was confirmed by protein sequence data in the
literature [Christie et al., (1987), FEES Letts. 214, 45-49]. The
bovine fetuin cDNA was labelled by the random-primer technique and
w#s used to screen a fetal sheep liver (pooled 40-60 cDNA
library. A cDNA encoding the whole of sheep fetuin was obtained and
was fully sequenced. The sheep fetuin cDNA was similarly labelled
and was used to screen an adult pig liver cDNA library. An almost
full-length pig fetuin clone was obtained and was sequenced. The
deduced amino acid sequences were confirmed by amino-terminal
protein sequence analysis by Dr. D.L. Christie of the glycoproteins
purified from plasma. During this project it was reported that the
protein encoded kyf rat clone pp(# [Auberger et ai., (1989), Cell
58, 631-640] showed strong homology to bovine fetuin and human
ag-HS glycoprotein. Further analysis, reported in this thesis,
demonstrates that clone pp63 encodes rat fetuin.

The three fetuin sequences reported in this thesis are
compared with the other known members of the mammalian fetuin
family: human ag-HS glycoprotein, the rat protein encoded by clone
pp63 and mouse fetuin. Sequence analysis reveals that fetuins
comprise three domains: at the amino-terminus two cystatin-like
domains and a unique carboxyl-terminal domain. A series of actual
or potential sites for post-translational modification are apparent
in the sequences.

By the techniques used (northern blot, RNAase protection assay
and polymerase chain reaction) fetuin expression could only be
detected in the liver. No fetuin mRNA could be detected in the
fetal brain, although the protein can be immunocytochemically
localised there. Data reported here show that in cattle, fetuin is
a positive acute phase protein. It has been reported that human aj-
HS glycoprotein and rat fetuin are negative acute phase proteins.

Item Type: Thesis (Doctoral)
Subjects: Q Science > QH Natural history > QH301 Biology
Organisations: University of Southampton
ePrint ID: 192429
Date :
Date Event
March 1991Published
Date Deposited: 11 Jul 2011 15:53
Last Modified: 18 Apr 2017 01:50
Further Information:Google Scholar

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