LFA-3 delta D2: a novel in vivo isoform of lymphocyte function-associated antigen 3.
Lymphocyte function-associated antigen 3 (LFA-3) has previously been described as occurring as two isomers in vivo, a transmembrane (TM) form and a glycosyl phosphatidylinositol (GPI)-linked form, differing only in their membrane anchoring mechanism. A third isoform, LFA-3 delta D2, which has the cytoplasmic tail of TM LFA-3 but a truncated extracellular domain, has been identified in vitro. We report that the LFA-3 delta D2 isoform, identified by RT-PCR analysis and DNA sequencing, is also present in vivo and appears to share a signal sequence with the TM and GPI isoforms. Expression of LFA-3 delta D2 was observed in both normal and diseased human buccal mucosa and gingiva. Thus, while specific functional differences between isoforms remain to be established, our results show that LFA-3 delta D2 is constitutively expressed in vivo, along with the other, previously described, isoforms of LFA-3.
Kirby
A C
AC
Department of Oral Medicine, Eastman Dental Institute, London, U.K.
Hill
V
V
Olsen
I
I
Porter
S R
SR
D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D018968:CD58 Antigens; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction
D015703:Antigens, CD; D018968:CD58 Antigens; D018076:DNA, Complementary; D008562:Membrane Glycoproteins