The DSB response elicited by ATM and its signaling network is subject to tight regulation at many levels with an emphasis on inhibitory regulation. ATM itself and H2afx are controlled by phosphatases, Mdc1 via protein stability, Rnf168 via ubiquitin-dependent targeting for proteasomal degradation and the extent of K63 ubiquination via inhibition of E2 ligase activity and/or deubiquitination. Tp53bp1 function is regulated via accessibility to modified chromatin in the absence of signal. For more details check PMID 24002223. The various regulatory aspects are listed by target(s) type(s) along with their associated genes.

ATM phosphatases
ATM phosphatases, which may exert opposing regulatory effects, include protein phosphatase 2, known as PP2A, Ppp5, known as Pp5 and Ppm1d, known as Wip1. The protein phosphatase 2 enzyme is composed of structural A and catalytic C subunits and a regulatory B subunit. Both A and C subunits are represented by two genes and there are several regulatory B genes. Together they form several kinds of holoenzymes that exhibit distinct characteristics and functions. The genes (a catalytic subunit for protein phosphatase 2) are listed with aliases in parentheses, full names and links to gene report pages:
Ppp2ca (Pp2a-alpha, Pp2ac, , Pp2a1, Pp2calpha) – protein phosphatase 2 catalytic subunit alpha
Ppp5c (Pp5, Ppp5) – protein phosphatase 5, catalytic subunit
Ppm1d (Wip1) – protein phosphatase, Mg2+/Mn2+ dependent, 1D

H2afx phosphatases
Ser139 phosphatases
Serine 139 phosphatases include some of the enzymes that also target ATM (see above), such as Ppp2ca and Ppm1d as well as Ppp4c, known as Pp4 and Ppp6c, known as Pp6. The genes are listed with aliases in parentheses, full names and links to gene report pages:
Ppp2ca (Pp2a-alpha, Pp2ac, , Pp2a1, Pp2calpha) – protein phosphatase 2 catalytic subunit alpha
Ppm1d (Wip1) – protein phosphatase, Mg2+/Mn2+ dependent, 1D
Ppp4c (PP4, PP4C, PPX) – protein phosphatase 4, catalytic subunit
Ppp6c (Pp6, PP6C, PP-V) – protein phosphatase 6, catalytic subunit

Tyr142 phosphatases
Tyrosine phosphorylation promotes recruitment of pro-apoptotic kinases; its reversal promotes Mdc1 binding and double-strand repair and it is carried out by tyrosine phosphatases. The genes are listed with aliases in parentheses, full names and links to gene report pages:
Eya1 (BOP, BOR, BOS1, OFC1, eyes absent homolog 1 (Drosophila)) – EYA transcriptional coactivator and phosphatase 1
Eya3 (eyes absent homolog 3 (Drosophila)) – EYA transcriptional coactivator and phosphatase 3

Mdc1 regulators
Mdc1 is regulated at the level of protein stability. Ring finger 4 (Rnf4) recognizes Mdc1 sumoylated by Pias1 and 3 and ubiquitylates it to promote its proteasomal degradation. The genes are listed with aliases in parentheses, full names and links to gene report pages:
Pias1 (DDXBP1) – protein inhibitor of activated STAT, 1
Pias4 (ZMIZ6) – protein inhibitor of activated STAT, 4
Rnf4 (SNURF) – ring finger protein 4

Rnf168 regulators
Rnf168 is regulated at the level of stability and also by counteracting its actions. Ubiquitination by the Trip12 and Ubr5 E3 ligases promotes its proteasomal degradation. Otub1 on the other hand, directly inhibits the E2 ubiquitin-conjugating enzymes such as Ube2n that functions together with Rnf168. The genes are listed with aliases in parentheses, full names and links to gene report pages:
Trip12 (Gtl6) – thyroid hormone receptor interactor 12
Ubr5 (DD5, EDD1, HYD) – ubiquitin protein ligase E3 component n-recognin 5
Otub1 (OTB1), OTU1, otubain-1) OTU deubiquitinase, ubiquitin aldehyde binding 1

K63 ubiquitination regulators
K63 polyubiquitination is central to the chromatin modulation that assembles effectors such as Brca1 and Tp53bp1 that dictate the course of repair pathway to follow. Several deubiquitylating enzymes are involved in the process. The genes are listed with aliases in parentheses, full names and links to gene report pages:
Brcc3 (BRISC complex subunit BRCC36) – BRCA1/BRCA2-containing complex, subunit 3
Psmd14 (PAD1, POH1, RPN11) – proteasome 26S subunit, non-ATPase 14
Usp3 (SIH003) – ubiquitin specific peptidase 3
Usp16 (UBP-M, UBPM) – ubiquitin specific peptidase 16
Usp44 – ubiquitin specific peptidase 44

Tp53bp1 regulation
As mentioned in the main text, the chromatin binding of Tp53bp1 is dependent upon the dual recognition of dimethylated and ubiquitinated histones, in addition to homo-oligomerization. In the absence of damage, the dimetylated H4 Lys20 (H4K2me2) is masked from a possible interaction with Tp53bp1 by its interaction with the polycomb protein L3mbtl1 and the Kdm4a demethylase, known as Jmjd2a (Jumonji domain-containing protein 2A). Activation of the ATM pathway leads to eviction of the polycomb protein by the valosin-containing protein (VCP) while the demethylase is targeted for degradation. The genes are listed with aliases in parentheses, full names and links to gene report pages:
L3mbtl1 (l(3)mbt-like 1 (Drosophila)) – L3MBTL1, histone methyl-lysine binding protein
Kdm4a (JMJD2, JMJD2A, lysine (K)-specific demethylase 4A) – lysine demethylase 4A
Vcp (p97, TER ATPase, TERA) – valosin-containing protein