The transcripts of zeta-crystallin, a lens protein related to the alcohol dehydrogenase family, are altered in a guinea-pig hereditary cataract.

Abstract

Zeta-Crystallin, a major component of the guinea-pig lens proteins, is distantly related to the enzymes of the zinc-containing alcohol dehydrogenase family (ADH). Analysis of the structural similarities between zeta-crystallin and ADH reveals that while characteristics important in maintaining the tertiary structure of the molecule appear conserved, the amino acids binding the catalytic zinc atom are absent in zeta-crystallin. Significantly, zeta-crystallin does not have ADH activity. Previous studies showed that the zeta-crystallin protein is modified in the lens of guinea-pigs affected with an autosomal dominant hereditary cataract. We have further investigated the molecular origin of the lens defect by examining the steady-state levels of zeta-crystallin transcripts in normal and mutant eyes. Our data indicate that no normal zeta-crystallin mRNA is present in the lens of the homozygous animals; instead, a cross-hybridizing lower molecular weight mRNA is detected at significantly reduced concentrations. Heterozygous lenses exhibit both mRNA species.

• Authors: T Borrás, H Jörnvall, A Rodokanaki, P Gonzalez, I Rodriguez, C Hernandez-Calzadilla
• Journal: Experimental eye research (Exp Eye Res) Vol. 50 Issue 6 Pg. 729-35 (Jun 1990) ISSN: 0014-4835 [Print] England
• PMID: 1695576 (Publication Type: Journal Article)

Chemical References

• Crystallins
• RNA

Topics

• Amino Acid Sequence
• Animals
• Cataract (genetics, metabolism)
• Crystallins (genetics)
• Guinea Pigs
• Molecular Sequence Data
• Protein Conformation
• RNA (analysis)
• Transcription, Genetic