cDNA from human ocular ciliary epithelium homologous to beta ig-h3 is preferentially expressed as an extracellular protein in the corneal epithelium.
The non-pigmented ciliary epithelium is largely responsible for the formation of aqueous humor in the mammalian eye. To provide a basis for studies at the molecular level, a directional expression cDNA library was constructed in Uni-ZAP XR vector from poly A+ RNA of the human non-pigmented ciliary epithelial derived ODM-2 cell line. Fifty-three cDNA clones were isolated from the library and characterized by partial sequence analysis. Approximately 49% of the clones exhibited homology with known genes in the GenBank/EMBL databases. The putative identification of these clones may reflect the transcriptional activity of the ODM-2 cells in culture. One of the identified clones, ODM-42-I, was found to be specific and highly expressed in the corneal epithelium. This clone had an exact match with a recently discovered human gene, beta ig-h3 (Skonier et al., 1992, DNA Cell Biol., 11:511-522), which codes a surface recognition protein, inducible by transforming growth factor beta (TGF-beta), and containing a putative binding site (RDG) for integrins. The ODM-42-I cDNA clone displays a distinctive pattern of expression found in the human eye, expressed almost exclusively in the cornea. Further studies, using sera from a synthetic peptide to the carboxy-terminal region of ODM-42-I, reveal that the protein is heterogeneous in charge and is preferentially expressed on the extracellular surface of corneal epithelial cells, and might share immunologic properties with integrins beta 1.
Escribano
J
J
Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut 06510.
Hernando
N
N
Ghosh
S
S
Crabb
J
J
Coca-Prados
M
M
D000818:Animals; D002460:Cell Line; D002924:Ciliary Body / Q000166:cytology / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics* / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D004728:Endothelium, Corneal / Q000378:metabolism*; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism*; D015723:Gene Library; D006801:Humans; D016023:Integrins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D017385:Sequence Homology; D014018:Tissue Distribution
D018076:DNA, Complementary; D016023:Integrins; D012333:RNA, Messenger