RAD54L explained

DNA repair and recombination protein RAD54-like is a protein that in humans is encoded by the RAD54L gene.^{[1] [2]}

The protein encoded by this gene belongs to the DEAD-like helicase superfamily, and shares similarity with Saccharomyces cerevisiae Rad54, a protein known to be involved in the homologous recombination and repair of DNA. This protein has been shown to play a role in homologous recombination related repair of DNA double-strand breaks. The binding of this protein to double-strand DNA induces a DNA topological change, which is thought to facilitate homologous DNA pairing, and stimulate DNA recombination.^[2]

RAD54 is one of the key proteins necessary for homologous recombination and DNA repair in many organisms. Without functional RAD54, tumor development is more likely. RAD54 was initially described in the budding yeast Saccharomyces cerevisiae as being a member of the evolutionarily conserved RAD52 epistasis group, which additionally includes RAD51, RAD52, RAD55, and RAD57 factors. This group is believed to be involved in DNA recombination events and repair mechanisms, especially those involving double-stranded DNA breaks during both mitosis and meiosis. Recently a human homologue of the yeast RAD54 was discovered and termed hRAD54.

Human gene

Human RAD54, or hRAD54, is linked to chromosome 1p32. It encodes a protein, composed of 747 amino acids, that is 52% identical to its yeast counterpart. These two proteins also share many functional similarities. The RAD54 encoded product is a member of the Swi2/Snf2 protein family, a member of the Swi2/Snf2 subfamily of ATPases. These protein products have homology in seven conserved helicase motifs. Purified hRAD54 has been shown to specifically exhibit DNA-dependent ATPase and supercoiling activities. hRAD54 transcripts are expressed primarily in the testis and thymus, with lower levels being found also in the small intestines, colon, breast, and prostate. Mutants of hRAD54 are extremely sensitive to x-rays, as well as methyl methanesulfonate (MMS). These mutants are most likely defective in both the spontaneous and induced mitotic recombination processes.

Function

The interaction between RAD54 and RAD51, another member of the RAD52 epistasis group, in humans is mediated by the N-terminal domain of the hRAD54 protein. This N-terminal end interacts with both the free and bound ends of the RAD51 protein. RAD54 moves along the length of the DNA, producing positive supercoils ahead of the replication protein movement and negative supercoils trailing the complex. The interaction with RAD51 enhances the ability of RAD54 to perform this supercoiling and strained opening activity. These proteins also work together to form DNA joints, with RAD54 specifically extending the joints and stabilizing the D-loops formed. An alternative function of RAD54 may be to remove RAD51 proteins after joints formation and recombination initiation has occurred.

Inactivation and cancer susceptibility

Defects in RAD51 are known to be associated with tumor development. Normally, RAD51 interacts with both BRCA1 and BRCA2 protein products to cause tumor suppression. This leads to the assumption that other members of the RAD52 epistasis group, including RAD54, are also important in tumor development and suppression because of their homologous relationship. RAD54’s involvement as a necessary recombinational protein is supported in the finding that there are mutations of RAD54 in a small percentage of studied breast and colon carcinomas, as well as several lymphomas.

Meiosis

The frequency of spontaneous chromosome breaks during meiosis was measured in the spermatocytes of both wild type mice and Rad54/Rad54B knockout mice.^[3] In the Rad54/Rad54B knockout mice, the spontaneous chromosome aberration frequency detected at metaphase 1 of meiosis was more than 10-fold higher than in the wild-type mice. This finding, and additional experimental findings, indicated that the RAD54/RAD54B proteins have a role in maintaining a stable karyotype during male meiosis.

Further reading

• Rasio D, Murakumo Y, Robbins D, Roth T, Silver A, Negrini M, Schmidt C, Burczak J, Fishel R, Croce CM . 6 . Characterization of the human homologue of RAD54: a gene located on chromosome 1p32 at a region of high loss of heterozygosity in breast tumors . Cancer Research . 57 . 12 . 2378–2383 . June 1997 . 9192813 .
• Golub EI, Kovalenko OV, Gupta RC, Ward DC, Radding CM . Interaction of human recombination proteins Rad51 and Rad54 . Nucleic Acids Research . 25 . 20 . 4106–4110 . October 1997 . 9321665 . 147015 . 10.1093/nar/25.20.4106 .
• Swagemakers SM, Essers J, de Wit J, Hoeijmakers JH, Kanaar R . The human RAD54 recombinational DNA repair protein is a double-stranded DNA-dependent ATPase . The Journal of Biological Chemistry . 273 . 43 . 28292–28297 . October 1998 . 9774452 . 10.1074/jbc.273.43.28292 . free . 1765/8917 . free .
• Matsuda M, Miyagawa K, Takahashi M, Fukuda T, Kataoka T, Asahara T, Inui H, Watatani M, Yasutomi M, Kamada N, Dohi K, Kamiya K . 6 . Mutations in the RAD54 recombination gene in primary cancers . Oncogene . 18 . 22 . 3427–3430 . June 1999 . 10362365 . 10.1038/sj.onc.1202692 . 36652599 .
• Carling T, Imanishi Y, Gaz RD, Arnold A . Analysis of the RAD54 gene on chromosome 1p as a potential tumor-suppressor gene in parathyroid adenomas . International Journal of Cancer . 83 . 1 . 80–82 . September 1999 . 10449612 . 10.1002/(SICI)1097-0215(19990924)83:1<80::AID-IJC15>3.0.CO;2-E . free .
• Bello MJ, de Campos JM, Vaquero J, Ruiz-Barnés P, Kusak ME, Sarasa JL, Rey JA . hRAD54 gene and 1p high-resolution deletion-mapping analyses in oligodendrogliomas . Cancer Genetics and Cytogenetics . 116 . 2 . 142–147 . January 2000 . 10640146 . 10.1016/S0165-4608(99)00122-3 .
• Pluth JM, Fried LM, Kirchgessner CU . Severe combined immunodeficient cells expressing mutant hRAD54 exhibit a marked DNA double-strand break repair and error-prone chromosome repair defect . Cancer Research . 61 . 6 . 2649–2655 . March 2001 . 11289143 .
• Ristic D, Wyman C, Paulusma C, Kanaar R . The architecture of the human Rad54-DNA complex provides evidence for protein translocation along DNA . Proceedings of the National Academy of Sciences of the United States of America . 98 . 15 . 8454–8460 . July 2001 . 11459989 . 37457 . 10.1073/pnas.151056798 . free . 2001PNAS...98.8454R .
• Ren B, Cam H, Takahashi Y, Volkert T, Terragni J, Young RA, Dynlacht BD . E2F integrates cell cycle progression with DNA repair, replication, and G(2)/M checkpoints . Genes & Development . 16 . 2 . 245–256 . January 2002 . 11799067 . 155321 . 10.1101/gad.949802 .
• Sigurdsson S, Van Komen S, Petukhova G, Sung P . Homologous DNA pairing by human recombination factors Rad51 and Rad54 . The Journal of Biological Chemistry . 277 . 45 . 42790–42794 . November 2002 . 12205100 . 10.1074/jbc.M208004200 . free .
• Leone PE, Mendiola M, Alonso J, Paz-y-Miño C, Pestaña A . Implications of a RAD54L polymorphism (2290C/T) in human meningiomas as a risk factor and/or a genetic marker . BMC Cancer . 3 . 6 . March 2003 . 12614485 . 152652 . 10.1186/1471-2407-3-6 . free .
• Kim J, Bhinge AA, Morgan XC, Iyer VR . Mapping DNA-protein interactions in large genomes by sequence tag analysis of genomic enrichment . Nature Methods . 2 . 1 . 47–53 . January 2005 . 15782160 . 10.1038/nmeth726 . 6135437 .
• Nicolas H. Thomä . Thomä NH, Czyzewski BK, Alexeev AA, Mazin AV, Kowalczykowski SC, Pavletich NP . Structure of the SWI2/SNF2 chromatin-remodeling domain of eukaryotic Rad54 . Nature Structural & Molecular Biology . 12 . 4 . 350–356 . April 2005 . 15806108 . 10.1038/nsmb919 . 3226377 .
• Al-Wahiby S, Wong HP, Slijepcevic P . Shortened telomeres in murine scid cells expressing mutant hRAD54 coincide with reduction in recombination at telomeres . Mutation Research . 578 . 1–2 . 134–142 . October 2005 . 15975611 . 10.1016/j.mrfmmm.2005.04.008 .
• Bugreev DV, Mazina OM, Mazin AV . Rad54 protein promotes branch migration of Holliday junctions . Nature . 442 . 7102 . 590–593 . August 2006 . 16862129 . 10.1038/nature04889 . 4324847 . 2006Natur.442..590B .
• Akiyama K, Yusa K, Hashimoto H, Poonepalli A, Hande MP, Kakazu N, Takeda J, Tachibana M, Shinkai Y . 6 . Rad54 is dispensable for the ALT pathway . Genes to Cells . 11 . 11 . 1305–1315 . November 2006 . 17054727 . 10.1111/j.1365-2443.2006.01020.x . 34879148 .

Notes and References

1. Kanaar R, Troelstra C, Swagemakers SM, Essers J, Smit B, Franssen JH, Pastink A, Bezzubova OY, Buerstedde JM, Clever B, Heyer WD, Hoeijmakers JH . 6 . Human and mouse homologs of the Saccharomyces cerevisiae RAD54 DNA repair gene: evidence for functional conservation . Current Biology . 6 . 7 . 828–838 . July 1996 . 8805304 . 10.1016/S0960-9822(02)00606-1 . free . 2195913 . 1765/3104 .
2. Web site: Entrez Gene: RAD54L RAD54-like (S. cerevisiae).
3. Russo A, Cordelli E, Salvitti T, Palumbo E, Pacchierotti F . Rad54/Rad54B deficiency is associated to increased chromosome breakage in mouse spermatocytes . Mutagenesis . 33 . 4 . 323–332 . October 2018 . 30204892 . 10.1093/mutage/gey027 . free .