scholarly journals Evolution of crystallins for a role in the vertebrate eye lens

2013 ◽  
Vol 22 (4) ◽  
pp. 367-380 ◽  
Author(s):  
Christine Slingsby ◽  
Graeme J. Wistow ◽  
Alice R. Clark
Keyword(s):  
Eye Lens ◽  
Vertebrate Eye

The vertebrate eye lens

Science ◽  
1977 ◽  
Vol 197 (4299) ◽  
pp. 127-138 ◽  
Author(s):  
H Bloemendal
Keyword(s):  
Eye Lens ◽  
Vertebrate Eye

scholarly journals Urochordate βγ-Crystallin and the Evolutionary Origin of the Vertebrate Eye Lens

2005 ◽  
Vol 15 (18) ◽  
pp. 1684-1689 ◽  
Author(s):  
Sebastian M. Shimeld ◽  
Andrew G. Purkiss ◽  
Ron P.H. Dirks ◽  
Orval A. Bateman ◽  
Christine Slingsby ◽  
...  
Keyword(s):  
Evolutionary Origin ◽  
Eye Lens ◽  
Vertebrate Eye

scholarly journals A nuclear yeast gene (GCY) encodes a polypeptide with high homology to a vertebrate eye lens protein

FEBS Letters ◽  
1988 ◽  
Vol 238 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Ulrich Oechsner ◽  
Viktor Magdolen ◽  
Wolfhard Bandlow
Keyword(s):  
Eye Lens ◽  
Lens Protein ◽  
High Homology ◽  
Yeast Gene ◽  
Eye Lens Protein ◽  
Vertebrate Eye

Unfolding and refolding of a quinone oxidoreductase: α-crystallin, a molecular chaperone, assists its reactivation

2001 ◽  
Vol 359 (3) ◽  
pp. 547-556 ◽  
Author(s):  
Shradha GOENKA ◽  
Bakthisaran RAMAN ◽  
Tangirala RAMAKRISHNA ◽  
Ch. Mohan RAO
Keyword(s):  
Tertiary Structure ◽  
Small Heat Shock Protein ◽  
Active State ◽  
Eye Lens ◽  
Quinone Oxidoreductase ◽  
Denatured State ◽  
Αb Crystallin ◽  
Partially Unfolded ◽  
Vertebrate Eye ◽  
Denatured States

α-Crystallin, a member of the small heat-shock protein family and present in vertebrate eye lens, is known to prevent the aggregation of other proteins under conditions of stress. However, its role in the reactivation of enzymes from their non-native inactive states has not been clearly demonstrated. We have studied the effect of α-crystallin on the refolding of ∊-crystallin, a quinone oxidoreductase, from its different urea-denatured states. Co-refolding ∊-crystallin from its denatured state in 2.5M urea with either calf eye lens α-crystallin or recombinant human αB-crystallin could significantly enhance its reactivation yield. αB-crystallin was found to be more efficient than αA-crystallin in chaperoning the refolding of ∊-crystallin. In order to understand the nature of the denatured state(s) of ∊-crystallin that can interact with α-crystallin, we have investigated the unfolding pathway of ∊-crystallin. We find that it unfolds through three distinct intermediates: an altered tetramer, a partially unfolded dimer, which is competent to fold back to its active state, and a partially unfolded monomer. The partially unfolded monomer is inactive, exhibits highly exposed hydrophobic surfaces and has significant secondary structural elements with little or no tertiary structure. This intermediate does not refold into the active state without assistance. α-Crystallin provides the required assistance and improves the reactivation yield several-fold.

α-Crystallins in the Vertebrate Eye Lens: Complex Oligomers and Molecular Chaperones

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Marc A. Sprague-Piercy ◽  
Megan A. Rocha ◽  
Ashley O. Kwok ◽  
Rachel W. Martin
Keyword(s):  
Posttranslational Modifications ◽  
Eye Lens ◽  
Annual Review ◽  
Publication Date ◽  
Binding Modes ◽  
Cryo Electron Microscopy ◽  
Αb Crystallin ◽  
C And N ◽  
Shock Proteins ◽  
Vertebrate Eye

α-Crystallins are small heat-shock proteins that act as holdase chaperones. In humans, αA-crystallin is expressed only in the eye lens, while αB-crystallin is found in many tissues. α-Crystallins have a central domain flanked by flexible extensions and form dynamic, heterogeneous oligomers. Structural models show that both the C- and N-terminal extensions are important for controlling oligomerization through domain swapping. α-Crystallin prevents aggregation of damaged β- and γ-crystallins by binding to the client protein using a variety of binding modes. α-Crystallin chaperone activity can be compromised by mutation or posttranslational modifications, leading to protein aggregation and cataract. Because of their high solubility and their ability to form large, functional oligomers, α-crystallins are particularly amenable to structure determination by solid-state NMR and solution NMR, as well as cryo-electron microscopy. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Morphological and elemental analysis of isolated incubated frog retina-choroid

1984 ◽  
Vol 42 ◽  
pp. 298-299
Author(s):  
B. J. Panessa-Warren ◽  
J. B. Warren ◽  
H. W. Kraner
Keyword(s):  
Elemental Analysis ◽  
Pigment Epithelium ◽  
Human Retina ◽  
Healthy Individuals ◽  
Anterior Portion ◽  
Pathological Conditions ◽  
Frog Retina ◽  
Isolated Retina ◽  
Vertebrate Eye ◽  
Retina Pigment Epithelium

Our previous studies have demonstrated that abnormally high amounts of calcium (Ca) and zinc (Zn) can be accumulated in human retina-choroid under pathological conditions and that barium (Ba), which was not detected in the eyes of healthy individuals, is deposited in the retina pigment epithelium (RPE), and to a lesser extent in the sensory retina and iris. In an attempt to understand how these cations can be accumulated in the vertebrate eye, a morphological and microanalytical study of the uptake and loss of specific cations (K, Ca,Ba,Zn) was undertaken with incubated Rana catesbiana isolated retina and RPE preparations. Large frogs (650-800 gms) were dark adapted, guillotined and their eyes enucleated in deep ruby light. The eyes were hemisected behind the ora serrata and the anterior portion of the eye removed. The eyecup was bisected along the plane of the optic disc and the two segments of retina peeled away from the RPE and incubated.

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