α-Crystallin, a small heat shock protein (sHSP), constitutes the major portion of eye lens cytoplasm and its concentration in the lens can reach up to 50% of the total protein. Like other sHSP, α-crystallin displays chaperone-like activity in suppressing the aggregation of various proteins and in preventing inactivation of enzymes due to heat and other stress conditions [1-6]. Hence, in additio...

PURPOSE The purpose of the study was to determine whether the autodegradation of human βA3-crystallin is due to its intrinsic protease activity. METHODS Recombinant His-tagged human βA3-crystallin was expressed in E. coli and purified by a Ni+2-affinity column chromatographic method. To determine protease activity, the purified crystallin was incubated for 24 h with either sodium deoxycholate...

The vertebrate lens is composed of two distinct cell types, the epithelial cells and the fiber cells. The absolute rate of synthesis of total protein and of purified cr-crystallin, a structural polymeric protein found in both cell types, has been calculated using the kinetics of [3H]leucine incorporation into organ-cultured lenses. The data show that in adult epithelial cells about 2% of Lu-cry...

PURPOSE Lens alpha-crystallins, composed of two subunits of alphaA- and alphaB-crystallin, form low molecular weight (LMW) water soluble aggregates with an average molecular mass of approximately 800 kDa. In the intact lens, some of the alpha-crystallins are associated with even larger high-molecular-weight (HMW) aggregates which are thought to be precursors of components found in the water ins...

m a-Crystallins were demonsl:rated recently to be involved fin interaction with a short element of the sense strand of the murine yDE/F-ctystallin genes immediately downstresm of the transcriptional initiation site @OTIS). The aim of the study was to demonstrate a consensus sequence and to test, if the interaction with a-crystallin is dependent on phospholylation. M&&& 3*P-labelled oligonucleot...

The cis-elements responsible for the high-level, lens-specific expression of the chicken beta B1-crystallin gene were investigated by generating mice harboring beta B1-crystallin promoter/chloramphenicol acetyl transferase (CAT) transgenes. Deletion of promoter sequences -434/-153 and -152/-127 as well as site-directed mutagenesis of the PL1 (-116/-102) and Pl2 (-90/-76) elements significantly ...

S-Crystallin is a major protein present in the lenses of cephalopods (octopus and squid). To facilitate the cloning of this crystallin gene, cDNA was constructed from the poly(A)+ mRNA of octopus lenses, and amplified by PCR for nucleotide sequencing. Sequencing of 10 of 15 positive clones coding for this crystallin revealed three distinct S-crystallin isoforms with 61-64% identity in nucleotid...

α-Crystallin is the principal lens protein which, in addition to its structural role, also acts as a molecular chaperone, to prevent aggregation and precipitation of other lens proteins. One of its two subunits, αBcrystallin, is also expressed in many non-lenticular tissues, and a natural missense mutation, R120G, has been associated with cataract and desminrelated myopathy, a disorder of skele...

PURPOSE The R120G mutation of alphaB-crystallin is known to cause desmin-related myopathy, but the mechanisms underlying the formation of cataract are not clearly established. We hypothesize that alteration of protein-protein interaction between R120G alphaB-crystallin and lens intermediate filament proteins is one of the mechanisms of congenital cataract. METHODS Protein-protein interactions...

PURPOSE We previously reported the differential expression and translation of mRNA and protein in dark- and light-adapted octopus retinas, which may result from cytoplasmic polyadenylation element (CPE)-dependent mRNA masking and unmasking. Here we investigate the presence of CPEs in alpha-tubulin and S-crystallin mRNA and report the identification of cytoplasmic polyadenylation element binding...