class=”kwd-title”>Key phrases: BRCA1 p300 CARM1 DNA damage protein methylation p21 Gadd45 cell cycle apoptosis cancer Copyright ? 2011 Landes Bioscience This article has been cited by other articles in PMC. cell death. Failure of cell cycle arrest DNA damage repair and apoptosis frequently contributes to cellular malignancies.1 Thus the DNA damage response pathway is branched and a decision is made as to whether cells will be repaired or destroyed. However the control of the decision is still poorly understood. Figure 1 The roles of CARM1 and coactivator methylation T 614 in DNA damage signaling pathway. DNA damage activates ATM kinase and promotes the activity of tumor suppressors p53 and BRCA1. CARM1 methylates coactivator p300 and histones and induces coactivator complex … DNA damage response processes are coordinated by tumor suppressor p53 a transcription regulator involved in both branches of the DNA damage response pathway by regulating expression of cell cycle and apoptosis regulators.2 The association of p53 with other protein factors (e.g. MDM2 53 p300/CBP) and posttranslational modifications of p53 may contribute to the branch stage decision.3 We recently noticed that proteins methylation by CARM1 (coactivator associated arginine methyltransferase 1) is necessary for activation of genes involved specifically in the cell cycle arrest branch from the DNA harm response pathway.4 We therefore claim that CARM1 is put to influence your choice stage between arrest/fix versus cell loss of life. Proteins arginine methylation can be catalyzed by people of the proteins arginine methyltransferase (PRMT) family members which currently offers ten people in mammalian cells.5 6 Proteins arginine methylation performs several roles in the DNA damage response pathway. PRMT5 methylates three arginines of tumor suppressor p53 and enhances the experience of p53 in assistance with Strap proteins.7 Transcriptional activation of Gadd45 (growth arrest and DNA damage-inducible 45α) by p53 in cell-free T 614 assays also needs methylation of histones H3 and H4 by PRMT4/ CARM1 and PRMT1.8 CARM1 methylates coactivator p300 at multiple sites also.4 6 Methylation of p300 specifically at Arg754 in the KIX area is necessary for induction of cell T 614 routine regulators like p21CIP1/WAF1 and Gadd45.4 p21CIP1/WAF1 an inhibitor of cyclin-dependent kinases binds towards the T 614 G1/S-promoting cyclin E/Cdk2 kinase and thereby causes a G1 to S cell routine arrest. Gadd45 affiliates with PCNA and it is involved with both cell routine arrest and nucleotide excision restoration. Lack of CARM1 methyltransferase activity resulted in lack of cell routine arrest in response to DNA harm.4 Although p21CIP1/WAF1 is a downstream focus on gene of p53 p21 expression is induced by DNA harm even in p53-deficient cells CARM1 is involved with p21 induction in p53-dependent and p53-independent pathways.4 CCNE2 Furthermore CARM1 can be mixed up in induction of other p53-independent CDK inhibitors like p27 (unpublished data). Therefore CARM1 and coactivator methylation possess important roles in cell cycle check point regulation by genotoxic stresses. However CARM1 is not required for the induction of apoptosis regulators like Bax (BCL2-associated X protein) or PUMA (p53 upregulated modulator of apoptosis) which are also p53 target genes. Instead expression levels of Bax4 and PUMA (unpublished data) are elevated in CARM1 knockout cells. Similarly expression of PUMA is T 614 also upregulated in p300 knockout cells. 9 This is reminiscent of BRCA1 which is essential for expression of T 614 p21 and Gadd45 not for Bax.10 Thus CARM1 p300 and BRCA1 are all required for activation of genes involved in the cell cycle arrest branch of the DNA damage response pathway. On the other hand genes in the apoptosis branch from the pathway such as for example Bax or PUMA may possess different coregulator requirements. Since CARM1 regulates the discussion between p300 and BRCA1 and therefore the activation of p21 and Gadd45 genes (Fig. 1) CARM1 can be within an ideal placement to regulate the branch stage decision in the DNA harm response pathway. CARM1 methyltransferase activity may modulate additional tumor suppressors for determination of cell destiny also. We speculate that post-translational adjustments of CARM1 protein-protein relationships or.