ties for control of this gene's expression. Structural 
and functional analysis of these transcripts is in 
progress. 
A gene transfer approach was also used to isolate 
a human cDNA that encodes a fucosyltransferase 
different from the H fucosyltransferase. Analysis of 
the catalytic properties of this enzyme indicates 
that it has the unique ability to generate two 
distinct glycosidic linkages. The substrate proper- 
ties of this enzyme are virtually identical to those 
exhibited by the Lewis blood group fuco- 
syltransferase. The cognate gene was localized to 
human chromosome 19, consistent with genetic 
linkage data for the Lewis locus. The sequence of 
this cDNA indicates that it also encodes a type II 
transmembrane protein. Surprisingly, despite the 
fact that the H and Lewis enzymes maintain identi- 
cal structural topologies and have nearly identical 
substrate requirements, no significant primary se- 
quence similarities can be found between them. 
One oligosaccharide product of this enzyme repre- 
sents a murine stage-specific embryonic antigen. 
Studies are in progress to define the developmental 
expression patterns of this gene, in preparation for 
transgenic animal experiments designed to explore 
PUBLICATIONS 
the function(s) of the cell surface molecules it de- 
termines. 
A murine galactosyltransferase cDNA has also 
been isolated by Dr. Lowe's laboratory, using gene 
transfer methods. This enzyme is also a type II 
transmembrane molecule but bears no primary 
structural similarity to any other glycosyltrans- 
ferase. Biochemical analyses using cell lines trans- 
fected with this gene have confirmed that the com- 
plement of oligosaccharide structures displayed on 
the cell surface reflects the kinds and specific activi- 
ties of the cognate glycosyltransferases within a 
cell. These studies also indicate that the dynamic 
changes in cell surface oligosaccharide structures 
that accompany development are associated with 
significant changes in glycosyltransferase gene ex- 
pression. Studies are in progress to define the ex- 
pression patterns of this gene during development, 
again in preparation for transgenic experiments de- 
signed to answer questions about the function(s) of 
cell surface oligosaccharide molecules during mam- 
malian development. 
Dr. Lowe is also Assistant Professor of Pathology 
at the University of Michigan Medical School. 
Articles 
Ernst, L.K., Rajan, VP, Larsen, R.D., Ruff, M.M., and Lowe, J. B. 1989- Stable expression of blood group H de- 
terminants and GDP-L-fucose:P-D-galactoside 2-a-L-fucosyltransferase in mouse cells after transfection with 
human DNA. J Biol Chem 264:3436-3447. 
Keren, D.F., Warren, J.S., and Lowe, J.B. 1988. Strategy to diagnose monoclonal gammopathies in serum: 
high-resolution electrophoresis, immunofixation, and k/\ quantification. Clin Chem 34:2196-2201. 
Rajan, VP, Larsen, R.D., Ajmera, S., Ernst, L.K., and Lowe, J.B. 1989. A cloned human DNA restriction frag- 
ment determines expression of a GDP-L-fucose:P-D-galactoside 2-a-L-fucosyltransferase in transfected cells. 
Evidence for isolation and transfer of the human H blood group locus. J Biol Chem 264:11158-11167. 
Yabkowitz, R., Lowe, J.B., and Dixit, VM. 1989- Expression and initial characterization of a recombinant 
human thrombospondin heparin binding domain. J Biol Chem 264:10888-10896. 
Zhu, X.-X., Kozarsky, K., Strahler, J.R., Eckerskorn, C, Lottspeich, F., Melhem, R., Lowe, J., Fox, D.A., Hanash, 
S.M., and Atweh, G.F. 1989. Molecular cloning of a novel human leukemia-associated gene: evidence of 
conservation in animal species. J Biol Chem 264:14556-14560. 
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