CRYGC explained

Crystallin, gamma C, also known as CRYGC, is a protein which in humans is encoded by the CRYGC gene.^{[1] [2]}

Function

Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of vertebrate eye lens and maintains the transparency and refractive index of the lens. Since lens central fiber cells lose their nuclei during development, these crystallins are made and then retained throughout life, making them extremely stable proteins. Mammalian lens crystallins are divided into alpha, beta, and gamma families; beta and gamma crystallins are also considered as a superfamily. Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Gamma-crystallins are a homogeneous group of highly symmetrical, monomeric proteins typically lacking connecting peptides and terminal extensions. They are differentially regulated after early development. Four gamma-crystallin genes (gamma-A through gamma-D) and three pseudogenes (gamma-E, gamma-F, gamma-G) are organized in a genomic segment as a gene cluster. Whether due to aging or mutations in specific genes, gamma-crystallins have been involved in cataract formation.

Interactions

CRYGC has been shown to interact with CRYBB2,^[3] CRYAA^[3] and CRYAB.^[3]

Further reading

• Graw J . The crystallins: genes, proteins and diseases . Biological Chemistry . 378 . 11 . 1331–48 . November 1997 . 9426193 . 10.1515/bchm.1997.378.11.1299 .
• Slingsby C, Clout NJ . Structure of the crystallins . Eye . 13 (Pt 3b) . 3. 395–402 . June 1999 . 10627816 . 10.1038/eye.1999.113 . 13 . free .
• Hearne CM, Todd JA . Trinucleotide repeat polymorphism at the CRYG1 locus . Nucleic Acids Research . 19 . 19 . 5450 . October 1991 . 1923840 . 328932 . 10.1093/nar/19.19.5450-a .
• Brakenhoff RH, Aarts HJ, Reek FH, Lubsen NH, Schoenmakers JG . Human gamma-crystallin genes. A gene family on its way to extinction . Journal of Molecular Biology . 216 . 3 . 519–32 . December 1990 . 2258929 . 10.1016/0022-2836(90)90380-5 .
• den Dunnen JT, van Neck JW, Cremers FP, Lubsen NH, Schoenmakers JG . Nucleotide sequence of the rat gamma-crystallin gene region and comparison with an orthologous human region . Gene . 78 . 2 . 201–13 . May 1989 . 2777080 . 10.1016/0378-1119(89)90223-0 .
• Shiloh Y, Donlon T, Bruns G, Breitman ML, Tsui LC . Assignment of the human gamma-crystallin gene cluster (CRYG) to the long arm of chromosome 2, region q33-36 . Human Genetics . 73 . 1 . 17–9 . May 1986 . 3011643 . 10.1007/BF00292656 . 27997711 .
• Lubsen NH, Renwick JH, Tsui LC, Breitman ML, Schoenmakers JG . A locus for a human hereditary cataract is closely linked to the gamma-crystallin gene family . Proceedings of the National Academy of Sciences of the United States of America . 84 . 2 . 489–92 . January 1987 . 3025877 . 304234 . 10.1073/pnas.84.2.489 . 1987PNAS...84..489L . free .
• Meakin SO, Du RP, Tsui LC, Breitman ML . Gamma-crystallins of the human eye lens: expression analysis of five members of the gene family . Molecular and Cellular Biology . 7 . 8 . 2671–9 . August 1987 . 3670288 . 367883 . 10.1128/mcb.7.8.2671 .
• Meakin SO, Breitman ML, Tsui LC . Structural and evolutionary relationships among five members of the human gamma-crystallin gene family . Molecular and Cellular Biology . 5 . 6 . 1408–14 . June 1985 . 4033658 . 366871 . 10.1128/mcb.5.6.1408 .
• den Dunnen JT, Moormann RJ, Cremers FP, Schoenmakers JG . Two human gamma-crystallin genes are linked and riddled with Alu-repeats . Gene . 38 . 1–3 . 197–204 . 1986 . 4065573 . 10.1016/0378-1119(85)90218-5 .
• Andley UP, Mathur S, Griest TA, Petrash JM . Cloning, expression, and chaperone-like activity of human alphaA-crystallin . The Journal of Biological Chemistry . 271 . 50 . 31973–80 . December 1996 . 8943244 . 10.1074/jbc.271.50.31973 . free .
• Lampi KJ, Ma Z, Shih M, Shearer TR, Smith JB, Smith DL, David LL . Sequence analysis of betaA3, betaB3, and betaA4 crystallins completes the identification of the major proteins in young human lens . The Journal of Biological Chemistry . 272 . 4 . 2268–75 . January 1997 . 8999933 . 10.1074/jbc.272.4.2268 . free .
• Héon E, Priston M, Schorderet DF, Billingsley GD, Girard PO, Lubsen N, Munier FL . The gamma-crystallins and human cataracts: a puzzle made clearer . American Journal of Human Genetics . 65 . 5 . 1261–7 . November 1999 . 10521291 . 1288278 . 10.1086/302619 .
• Ren Z, Li A, Shastry BS, Padma T, Ayyagari R, Scott MH, Parks MM, Kaiser-Kupfer MI, Hejtmancik JF . A 5-base insertion in the gammaC-crystallin gene is associated with autosomal dominant variable zonular pulverulent cataract . Human Genetics . 106 . 5 . 531–7 . May 2000 . 10914683 . 10.1007/s004390000289 . 2027.42/42265 . free .
• Fu L, Liang JJ . Detection of protein-protein interactions among lens crystallins in a mammalian two-hybrid system assay . The Journal of Biological Chemistry . 277 . 6 . 4255–60 . February 2002 . 11700327 . 10.1074/jbc.M110027200 . free .
• Fu L, Liang JJ . Conformational change and destabilization of cataract gammaC-crystallin T5P mutant . FEBS Letters . 513 . 2–3 . 213–6 . February 2002 . 11904153 . 10.1016/S0014-5793(02)02313-X . 84645424 .
• Santhiya ST, Shyam Manohar M, Rawlley D, Vijayalakshmi P, Namperumalsamy P, Gopinath PM, Löster J, Graw J . Novel mutations in the gamma-crystallin genes cause autosomal dominant congenital cataracts . Journal of Medical Genetics . 39 . 5 . 352–8 . May 2002 . 12011157 . 1735119 . 10.1136/jmg.39.5.352 .
• MacCoss MJ, McDonald WH, Saraf A, Sadygov R, Clark JM, Tasto JJ, Gould KL, Wolters D, Washburn M, Weiss A, Clark JI, Yates JR . Shotgun identification of protein modifications from protein complexes and lens tissue . Proceedings of the National Academy of Sciences of the United States of America . 99 . 12 . 7900–5 . June 2002 . 12060738 . 122992 . 10.1073/pnas.122231399 . 2002PNAS...99.7900M . free .

Notes and References

1. den Dunnen JT, Moormann RJ, Cremers FP, Schoenmakers JG . Two human gamma-crystallin genes are linked and riddled with Alu-repeats . Gene . 38 . 1–3 . 197–204 . 1985 . 4065573 . 10.1016/0378-1119(85)90218-5 .
2. Web site: Entrez Gene: CRYGC crystallin, gamma C.
3. Fu L, Liang JJ . Detection of protein-protein interactions among lens crystallins in a mammalian two-hybrid system assay . The Journal of Biological Chemistry . 277 . 6 . 4255–60 . February 2002 . 11700327 . 10.1074/jbc.M110027200 . free .