Molecular cloning of a new angiopoietinlike factor from the human cornea.
OBJECTIVE
To isolate tissue-specific gene products that contribute to corneal integrity.


METHODS
A cDNA library was constructed and differentially hybridized. Cornea-specific clones were purified and further characterized.


RESULTS
In this study cornea-specific gene products were isolated by differential cDNA hybridization. In addition to known cornea-specific gene products, a transcript was isolated coding for a protein homologous to the angiopoietins, a recently described family of (anti)angiogenic factors. Subsequently, the full cDNA was sequenced, and the identified open reading frame was named cornea-derived transcript 6 (CDT6). Similar to the angiopoietins, CDT6 contains a hydrophobic NH2-terminal sequence, a coiled-coil domain, and a COOH-terminal fibrinogenlike domain. Expression of CDT6 could be detected only in the cornea and not in several other adult human tissues. Within the cornea, expression of CDT6 is confined to the stromal layer.


CONCLUSIONS
The human cornea shows high-level expression of a gene product homologous to the (anti)angiogenic factors, the angiopoietins. This homology, together with stromal-specific expression, suggests that this factor may contribute to the avascularity of the human cornea.
Peek
R
R
Netherlands Ophthalmic Research Institute, Amsterdam.
van Gelderen
B E
BE
Bruinenberg
M
M
Kijlstra
A
A
D000595:Amino Acid Sequence; D043925:Angiogenesis Inducing Agents / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D003315:Cornea / Q000737:chemistry* / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000032:analysis; D005136:Eye Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016366:Open Reading Frames / Q000235:genetics; D012313:RNA / Q000302:isolation & purification; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA
D043925:Angiogenesis Inducing Agents; D017931:DNA Primers; D018076:DNA, Complementary; D005136:Eye Proteins; D012333:RNA, Messenger; D012313:RNA