RAD9/YDR217C Summary Help

Standard Name RAD9 1, 2
Systematic Name YDR217C
Feature Type ORF, Verified
Description DNA damage-dependent checkpoint protein; required for cell-cycle arrest in G1/S, intra-S, and G2/M, plays a role in postreplication repair (PRR) pathway; transmits checkpoint signal by activating Rad53p and Chk1p; hyperphosphorylated by Mec1p and Tel1p; multiple cyclin dependent kinase consensus sites and the C-terminal BRCT domain contribute to DNA damage checkpoint activation; Rad9p Chk1 Activating Domain (CAD) is phosphorylated at multiple sites by Cdc28p/Clb2p (3, 4, 5, 6, 7 and see Summary Paragraph)
Name Description RADiation sensitive 8
Chromosomal Location
ChrIV:903480 to 899551 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: 126 cM
Gene Ontology Annotations All RAD9 GO evidence and references
  View Computational GO annotations for RAD9
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 4 genes
Classical genetics
reduction of function
Large-scale survey
663 total interaction(s) for 356 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 7
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 18
  • Biochemical Activity: 5
  • Co-localization: 1
  • Co-purification: 1
  • PCA: 2
  • Protein-peptide: 3
  • Reconstituted Complex: 7
  • Two-hybrid: 10

Genetic Interactions
  • Dosage Growth Defect: 4
  • Dosage Lethality: 2
  • Negative Genetic: 86
  • Phenotypic Enhancement: 244
  • Phenotypic Suppression: 62
  • Positive Genetic: 7
  • Synthetic Growth Defect: 103
  • Synthetic Lethality: 54
  • Synthetic Rescue: 46

Expression Summary
Length (a.a.) 1,309
Molecular Weight (Da) 148,396
Isoelectric Point (pI) 5.06
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIV:903480 to 899551 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: 126 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..3930 903480..899551 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000002625

RAD9 encodes an adaptor protein required for S. cerevisiae cell cycle checkpoint function. By mediating phosphorylation of important effector kinases, Rad9p facilitates the amplification of initial signals in response to DNA damage (reviewed in 3). Because of the ability of Rad9p to associate with double-stranded breaks, it is speculated that Rad9p also initiates these checkpoint signal transduction cascades by acting as a DNA damage sensor (9). Rad9p is required throughout the cell cycle; it has been shown to function at G1/S, intra-S, and G2/M (10, 11, 12).

Rad9p is phosphorylated during normal progression of the cell cycle, but becomes hyperphosphorylated by Mec1p and Tel1p in response to DNA damage (13, 14). Activated Rad9p then stimulates Mec1p phosphorylation of the effector kinases Chk1p and Rad53p (15, 16, 17). Chk1p and Rad53p phosphorylation leads to various processes associated with cellular arrest, such as transcriptional upregulation of DNA damage repair genes, transcriptional repression of cyclins, and stabilization of replication forks (reviewed in 18 and 19).

Rad9p has two BRCT (BRCA1 C-terminus) domains in its C-terminus that facilitate Rad9p-Rad9p interaction after DNA damage (20). It also has a tandem tudor domain that binds to double-stranded DNA (21). Rad9p purifies in two distinct complexes, a larger 850 kDa complex and a smaller 560 kDa complex. In addition to Rad9p, both complexes contain the chaperone proteins Ssa1p and Ssa2p and the smaller complex also includes Rad53p (22).

RAD9 null mutants are viable but exhibit sensitivity to X-ray and UV irradation, fail to arrest in response to DNA damage, and are prone to chromosomal instability (12, 23, 24). The RAD9 ortholog in S. pombe is crb2 (25). No single human ortholog has been identified; instead, in humans there exists a family of proteins, which includes BRCA1 (OMIM) and 53BP1 (OMIM), that contain tandem BRCT domains (26, 27). S. pombe crb2 and human 53BP1, like Rad9p, also contain tandem tudor domains (21).

Last updated: 2008-10-21 Contact SGD

References cited on this page View Complete Literature Guide for RAD9
1) Schiestl RH, et al.  (1989) Cloning and sequence analysis of the Saccharomyces cerevisiae RAD9 gene and further evidence that its product is required for cell cycle arrest induced by DNA damage. Mol Cell Biol 9(5):1882-96
2) Dowling, E.L.  (1985) Ph.D. thesis
3) Toh GW and Lowndes NF  (2003) Role of the Saccharomyces cerevisiae Rad9 protein in sensing and responding to DNA damage. Biochem Soc Trans 31(Pt 1):242-6
4) Ubersax JA, et al.  (2003) Targets of the cyclin-dependent kinase Cdk1. Nature 425(6960):859-64
5) Barbour L, et al.  (2006) DNA damage checkpoints are involved in postreplication repair. Genetics 174(4):1789-800
6) Wang G, et al.  (2012) Multiple phosphorylation of Rad9 by CDK is required for DNA damage checkpoint activation. Cell Cycle 11(20):3792-800
7) Abreu CM, et al.  (2013) Site-specific phosphorylation of the DNA damage response mediator rad9 by cyclin-dependent kinases regulates activation of checkpoint kinase 1. PLoS Genet 9(4):e1003310
8) Prakash L  (1974) Lack of chemically induced mutation in repair-deficient mutants of yeast. Genetics 78(4):1101-18
9) Naiki T, et al.  (2004) Association of Rad9 with double-strand breaks through a Mec1-dependent mechanism. Mol Cell Biol 24(8):3277-85
10) Siede W, et al.  (1993) RAD9-dependent G1 arrest defines a second checkpoint for damaged DNA in the cell cycle of Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 90(17):7985-9
11) Paulovich AG, et al.  (1997) RAD9, RAD17, and RAD24 are required for S phase regulation in Saccharomyces cerevisiae in response to DNA damage. Genetics 145(1):45-62
12) Weinert TA and Hartwell LH  (1988) The RAD9 gene controls the cell cycle response to DNA damage in Saccharomyces cerevisiae. Science 241(4863):317-22
13) Vialard JE, et al.  (1998) The budding yeast Rad9 checkpoint protein is subjected to Mec1/Tel1-dependent hyperphosphorylation and interacts with Rad53 after DNA damage. EMBO J 17(19):5679-88
14) Emili A  (1998) MEC1-dependent phosphorylation of Rad9p in response to DNA damage. Mol Cell 2(2):183-9
15) Blankley RT and Lydall D  (2004) A domain of Rad9 specifically required for activation of Chk1 in budding yeast. J Cell Sci 117(Pt 4):601-8
16) Ma JL, et al.  (2006) Activation of the checkpoint kinase Rad53 by the phosphatidyl inositol kinase-like kinase Mec1. J Biol Chem 281(7):3954-63
17) Sweeney FD, et al.  (2005) Saccharomyces cerevisiae Rad9 acts as a Mec1 adaptor to allow Rad53 activation. Curr Biol 15(15):1364-75
18) Chen Y and Sanchez Y  (2004) Chk1 in the DNA damage response: conserved roles from yeasts to mammals. DNA Repair (Amst) 3(8-9):1025-32
19) Weinert T  (1998) DNA damage checkpoints update: getting molecular. Curr Opin Genet Dev 8(2):185-93
20) Soulier J and Lowndes NF  (1999) The BRCT domain of the S. cerevisiae checkpoint protein Rad9 mediates a Rad9-Rad9 interaction after DNA damage. Curr Biol 9(10):551-4
21) Lancelot N, et al.  (2007) The checkpoint Saccharomyces cerevisiae Rad9 protein contains a tandem tudor domain that recognizes DNA. Nucleic Acids Res 35(17):5898-912
22) van den Bosch M and Lowndes NF  (2004) Remodelling the Rad9 checkpoint complex: preparing Rad53 for action. Cell Cycle 3(2):119-22
23) Weinert TA and Hartwell LH  (1990) Characterization of RAD9 of Saccharomyces cerevisiae and evidence that its function acts posttranslationally in cell cycle arrest after DNA damage. Mol Cell Biol 10(12):6554-64
24) Fasullo M, et al.  (1998) The Saccharomyces cerevisiae RAD9 checkpoint reduces the DNA damage-associated stimulation of directed translocations. Mol Cell Biol 18(3):1190-200
25) Willson J, et al.  (1997) Isolation and characterization of the Schizosaccharomyces pombe rhp9 gene: a gene required for the DNA damage checkpoint but not the replication checkpoint. Nucleic Acids Res 25(11):2138-46
26) Alpha-Bazin B, et al.  (2005) Boundaries and physical characterization of a new domain shared between mammalian 53BP1 and yeast Rad9 checkpoint proteins. Protein Sci 14(7):1827-39
27) Bork P, et al.  (1997) A superfamily of conserved domains in DNA damage-responsive cell cycle checkpoint proteins. FASEB J 11(1):68-76