| Modification Notes |
Crystallins are divided into two classes: taxon-specific, or enzyme, and ubiquitous. The ubiquitous crystallins constitute the major proteins of the vertebrate eye lens, where they maintain the transparency and refractive index of the lens. The taxon-specific crystallins, also designated phylogenetically-restricted crystallins, include ¬-, µ-, and Ω-crystallin, which all share homology to various enzymes. Ω-crystallin/quinone reductase is present at low levels in human lens tissue. It has NADPH-dependent quinone reductase activity distinct from other known quinone reductases, and may play a role as a pH response element-binding protein. CRYZL1 (Ω-crystallin-like 1 protein) shares a high degree of homology with Ω-crystallin. CRYZL1 is expressed at various levels in heart, brain, skeletal muscle, kidney, pancreas, liver and lung. |