PMID:7628452

Citation	Kamachi, Y, Sockanathan, S, Liu, Q, Breitman, M, Lovell-Badge, R and Kondoh, H (1995) Involvement of SOX proteins in lens-specific activation of crystallin genes. EMBO J. 14:3510-9
Abstract	We have studied the mechanism of delta 1-crystallin gene activation, which occurs early in lens cell differentiation, and have previously shown that an essential element of the delta 1-crystallin enhancer is bound by a group of nuclear factors, delta EF2, among which delta EF2a is highly enriched in lens cells. In this report we show that the cDNA of delta EF2a codes for the chicken SOX-2 protein (cSOX-2), which is structurally related to the sex-determining factor SRY. Sox-2 is expressed at high levels in the early developing lens in both chicken and mouse embryos. Overexpression of delta EF2a/cSOX-2 increased delta 1-crystallin enhancer activity to a plateau in lens cells, but not in fibroblasts, consistent with the previously drawn conclusion that delta EF2a activates transcription only in concert with another factor present in the lens. This result supports the model that SOX proteins act as architectural components in the activating complex formed on an enhancer, as indicated for another HMG domain protein, lymphoid enhancer binding factor 1 (LEF-1). We also show that SOX protein binding is essential for lens-specific promoter activity of the mouse gamma F-crystallin gene. This work is the first to show delta- and gamma-crystallin genes as examples of direct regulatory targets of SOX proteins and provides evidence that diversified crystallin genes are regulated, at least partly, by a common mechanism.
Links	PubMed PMC394419
Keywords	Amino Acid Sequence; Animals; Base Sequence; Cells, Cultured; Chickens; Cloning, Molecular; Crystallins/genetics; Crystallins/metabolism; DNA, Complementary; DNA-Binding Proteins/chemistry; DNA-Binding Proteins/genetics; DNA-Binding Proteins/physiology; Enhancer Elements, Genetic; Gene Expression Regulation, Developmental; HMGB Proteins; Humans; Lens, Crystalline/embryology; Lens, Crystalline/metabolism; Molecular Sequence Data; Nuclear Proteins/chemistry; Nuclear Proteins/genetics; Nuclear Proteins/physiology; Peptides; Promoter Regions, Genetic; Protein Binding; SOXB1 Transcription Factors; Sequence Homology, Amino Acid; Transcription Factors; Transcriptional Activation
edit table

Annotations

Gene product	Qualifier	GO ID	GO term name	Evidence Code	with/from	Aspect	Notes	Status
edit table

References

See Help:References for how to manage references in GONUTS.