Structural organization of the rat thy-1 gene.
Thy-1 is a differentiation marker expressed predominantly on thymocytes, T cells and brain tissue. Its presence on murine peripheral T cells but not B cells has long been used to distinguish between these two populations of lymphocytes. Although analogues of Thy-1 have been described in several mammalian species, its tissue distribution in different species varies widely, precluding its use as T-cell-specific marker. The Thy-1 molecule is a cell-surface glycoprotein of relative molecular mass 18,000, one-third of which represents carbohydrate; the protein moieties of the rat and murine Thy-1 molecules have been sequenced and found to consist of 111 and 112 amino acids, respectively. An unusual aspect of Thy-1 is the apparent absence of a hydrophobic segment comparable to that observed in other membrane glycoproteins which would allow integration of Thy-1 within the membrane lipid bilayer. This has prompted speculation that Thy-1 is anchored to the cell surface by some other hydrophobic component such as glycolipid. Here we report the structure of thy-1 complementary DNA and genomic clones and describe the exon-intron organization of the gene. More importantly, our data indicate that Thy-1 is initially synthesized as a molecule of 142 amino acids, 31 amino acids longer at the carboxyl end than the Thy-1 molecule isolated and characterized by Campbell et al. An extremely hydrophobic region of 20 amino acids lies within this 31-amino acid stretch and may represent the transmembrane segment responsible for anchoring Thy-1 to the cell membrane.
Seki
T
T
Moriuchi
T
T
Chang
H C
HC
Denome
R
R
Silver
J
J
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000276:immunology*; D001483:Base Sequence; D004247:DNA; D004274:DNA, Recombinant; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger; D051381:Rats; D018800:Thy-1 Antigens
D000954:Antigens, Surface; D004274:DNA, Recombinant; D012333:RNA, Messenger; D018800:Thy-1 Antigens; D004247:DNA