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.
Section of Biochemistry, Faculty of Pharmacy, Meijo University, Yagotoyama, Nagoya, Japan. mtakeuch@ccmfs.meijo-u.ac.jp
Noriko
N
Takeuchi
Akie
A
Ouchida
Akira
A
Kamei
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