BACKGROUND Congenital cataract is the most frequent cause of blindness during infancy or early childhood. To date, more than 40 loci associated with congenital cataract have been identified, including at least 26 genes on different chromosomes associated with inherited cataract. This present study aimed to identify the genetic mutation in a six-generation Chinese family affected with congenital...

The cells of most mammalian organs are connected by groups of cell-to-cell channels called gap junctions. Gap junction channels are made from the connexin (Cx) family of proteins. There are at least 20 isoforms of connexins, and most tissues express more than 1 isoform. The lens is no exception, as it expresses three isoforms: Cx43, Cx46, and Cx50. A common role for all gap junctions, regardles...

PURPOSE To identify mutations in 12 genes in Chinese families with congenital cataracts. METHODS Twenty five families with congenital cataracts involved in this study. The coding exons and adjacent intronic regions of 12 genes were analyzed by cycle sequencing, including the alpha A crystallin (CRYAA), alpha B crystallin (CRYAB), beta A1 crystallin (CRYBA1), beta A4 crystallin (CRYBA4), beta ...

Genetic factors have an important role in the development of glaucoma; however, the exact genetic defects remain to be identified in the majority of patients. Glaucoma is frequently observed in patients with anterior segment dysgenesis (ASD), microcornea or microphthalmia. The present study aimed to detect the potential mutations in the genes associated with ASD, microcornea and microphthalmia ...

PURPOSE Fiber cells of the ocular lens are bounded by a highly specialized plasma membrane. Despite the pivotal role that membrane proteins play in the physiology and pathophysiology of the lens, our knowledge of the structure and composition of the fiber cell plasma membrane remains fragmentary. In the current study, we utilized mass spectrometry-based shotgun proteomics to provide a comprehen...

Connexins form gap junction channels that provide a hydrophilic path between cell interiors. Some connexins, particularly the lens connexins, Cx46 and Cx50 and their orthologs, can form functional hemichannels in nonjunctional membranes. These hemichannels are a nonselective conduit to the extracellular medium and may jeopardize cell survival. The physiological function of hemichannels has rema...

Connexin (Cx) 45.6, an avian counterpart of rodent Cx50, is phosphorylated in vivo, but the sites and function of the phosphorylation have not been elucidated. Our peptide mapping experiments showed that the Ser(363) site in the carboxyl (COOH) terminus of Cx45.6 was phosphorylated and that this site is within casein kinase (CK) II consensus sequence, although showing some similarity to CKI seq...

Gap junctions are composed of proteins called connexins (Cx) and facilitate both ionic and biochemical modes of intercellular communication. In the lens, Cx46 and Cx50 provide the gap junctional coupling needed for homeostasis and growth. In mice, deletion of Cx46 produced severe cataracts, whereas knockout of Cx50 resulted in significantly reduced lens growth and milder cataracts. Genetic repl...

Both connexins and signal transduction pathways have been independently shown to play critical roles in lens homeostasis, but little is known about potential cooperation between these two intercellular communication systems. To investigate whether growth factor signaling and gap junctional communication interact during the development of lens homeostasis, we examined the effect of mitogen-activ...

We previously reported that, among the three connexins expressed in chick lens, overexpression of connexin (Cx) 45.6, not Cx43 or Cx56, stimulates lens cell differentiation; however, the underlying mechanism responsible for this effect is unclear. Here, we took advantage of naturally occurring loss-of-gap-junction function mutations of Cx50 (ortholog of chick Cx45.6) and generated the correspon...