C-terminal truncation of alpha-crystallin in hereditary cataractous rat lens.
C-Terminal truncated alpha-crystallins have been found in lenses of hereditary cataractous rat ICR/f, including two truncated alphaB-crystallins and several truncated alphaA-crystallins. These truncated crystallins probably resulted from degradation by m-calpain and Lp82. The alphaB-crystallin with five amino acid residues deleted showed decreased chaperone activity. Compared with alpha-crystallins from the normal rat lenses, overall chaperone activity of alpha-crystallins from the mutant lenses, including the above truncated alphaB-crystallin, was remarkably reduced. The decreased chaperone activity accompanying the increase in C-terminal truncated alpha-crystallins may cause the insolubilization of many proteins in the mutant lenses, which it is likely to lead to the progression of cataract formation.
Takeuchi
Noriko
N
Section of Biochemistry, Faculty of Pharmacy, Meijo University, Yagotoyama, Nagoya, Japan. mtakeuch@ccmfs.meijo-u.ac.jp
Ouchida
Akie
A
Kamei
Akira
A
D000595:Amino Acid Sequence; D000818:Animals; D002386:Cataract / Q000235:genetics*; D007908:Lens, Crystalline / Q000737:chemistry*; D008027:Light; D018832:Molecular Chaperones / Q000737:chemistry*; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D012542:Scattering, Radiation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors; D038202:alpha-Crystallin A Chain / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D038203:alpha-Crystallin B Chain / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification
D018832:Molecular Chaperones; D038202:alpha-Crystallin A Chain; D038203:alpha-Crystallin B Chain