Cloning and expression of cDNA for a human Gal(beta1-3)GalNAc alpha2,3-sialyltransferase from the CEM T-cell line.
Complementary DNA encoding a human Gal(beta1-3)GalNAc alpha2,3-sialyltransferase type II (hST3Gal II) was cloned from a CEM T-cell cDNA library using a 23-base oligonucleotide probe. The sequence of this probe was established on the basis of a slightly divergent sialylmotif L that was obtained by polymerase chain reaction with degenerate oligonucleotide primers based on the conserved sialylmotif L of mammalian Gal(beta1-3)GalNAc alpha2,3-sialyltransferases. It was thus confirmed that a short oligonucleotide probe may be sensitive and highly specific. The nucleotide and amino acid sequences of hST3Gal II show, respectively, 56.3% and 49.3% similarity to hST3Gal I [Kitagawa, H. & Paulson, J. C. (1994) J. Biol. Chem. 269, 17872-17878] and 88.1% and 93.7% similarity to murine ST3Gal II [Lee, Y. C., Kojima, N., Wada, E., Kurosawa, N., Nakaoka, T., Hamamoto, T. & Tsuji, S. (1994) J. Biol. Chem. 269, 10028-10033]. hST3Gal II mRNA was highly expressed in heart, liver, skeletal muscle and various lymphoid tissues but not in brain and kidney. A soluble form of hST3Gal II expressed in COS-7 cells was tested in vitro for substrate specificity and kinetic properties. Asialofetuin and asialo-bovine submaxillary mucin appeared better substrates for hST3Gal II than for its murine counterpart as previously reported [Kojima, N., Lee, Y.-C., Hamamoto, T., Kurosawa, N. & Tsuji, S. (1994) Biochemistry 33, 5772-5776]. In previous studies, we have shown hyposialylation of O-glycans attached to two major lymphocyte CD43 and CD45 cell surface molecules in human-immunodeficiency-virus-1(HIV-1)-infected T-cell lines. Since comparable levels of hST3Gal I and hST3Gal II mRNA and enzymatic activity were observed in parental and HIV-1-infected CEM T-cell lysates, the sialylation defect associated with HIV infection of this cell line is probably due to a mechanism different from a simple altered catalytic activity of these sialyltransferases.
Giordanengo
V
V
Laboratoire de Virologie, Faculté de Médecine, Nice, France.
Bannwarth
S
S
Laffont
C
C
Van Miegem
V
V
Harduin-Lepers
A
A
Delannoy
P
P
Lefebvre
J C
JC
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002460:Cell Line; D017931:DNA Primers; D018076:DNA, Complementary; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D012799:Sialyltransferases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D013601:T-Lymphocytes; D014162:Transfection
D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; D012799:Sialyltransferases; C029156:N-acetyllactosaminide alpha-2,3-sialyltransferase