MAD1L1 (mitotic arrest deficient 1 like 1)

2018-02-01   Keli Lima , Joao Agostinho Machado-Neto 




MAD1L1 is coiled-coil protein that binds to improperly attached kinetochrore, what results in recruitment and interaction with MAD2L1, activation of the mitotic checkpoint complex, inhibition of the anaphase-promoting complex\/cyclosome and cell cycle arrest. During interphase, MAD1L1 regulates mitosis entrance at nuclear pore complexes (MAD2L1-dependent mechanism) and Golgi apparatus-related functions (MAD2L1-independent mechanism). Alterations in MAD1L1 are associated with chromosomal instability, aneuploidy, and cancer susceptibility. The present review contains data on MAD1L1 DNA, RNA, protein encoded and function.



The entire MAD1L1 gene is approximately 417.1 Kb (start: 1815792 and end: 2232971 bp; orientation: Minus strand). The MAD1L1 gene encodes for 6 transcript variants. The transcript variant 1 (start: 1815792 and end: 2232948 bp; orientation: Minus strand; 19 exons; mRNA: 2754 bp) is the longest transcript variant. Transcript variant 2 (mRNA: 2717 bp), transcript variant 3 (mRNA: 2714 bp) and transcript variant 4 (mRNA: 2538 bp) differs in the 5 UTR compared to transcript variant 1. The transcript variants 1-4 encode the protein isoform a (718 aa protein). The transcript variant 5 (mRNA: 2376 bp; 17 exons) lacks some exons in the 5 UTR and displays an alternate exon in the 5 coding region, what results in an alternative start codon, frameshift, and a shorter and distinct protein (isoform b; 626 aa). The transcript variant 6 is the shortest transcript variant (start: 1815792 and end: 1940550 bp; 4 exons; mRNA: 1318 bp), it displays an alternative 5-terminal exon, uses an in-frame start codon and encodes the protein isoform c (174 aa).


Atlas Image
Figure 1. MAD1L1 protein structure. MAD1L1 protein contains a MAD1L1 oligomerization domain, MAD2L1-binding domain and RLK motif (Arg-Leu-Lys; essential for BUB1 and BUB3 interactions). This figure was adapted from Canman et al., 2002; Sironi et al., 2002.


MAD1L1 is a 718-residue coiled-coil protein that interacts with MAD2L1, and is composite of a MAD1L1 oligomerization domain, MAD2L1-binding domain and RLK motif (Arg-Leu-Lys; essential for BUB1 and BUB3 interactions) (Canman et al., 2002; Sironi et al., 2002) (Figure 1). MAD1L1-MAD2L1 complexes form a tetramer-like structure due to the parallel intermolecular coiled-coil between α 1 helices from different MAD1L1 molecules (Nasmyth, 2005; Sironi et al., 2002).




During mitosis, MAD1L1 is localized predominantly at unattached kinetochore. During interphase, MAD1L1 is localized in perinuclear region, nuclear pore complex, centrosome and Golgi apparatus (Campbell et al., 2001; Rodriguez-Bravo et al., 2014; Wan et al., 2014).
Atlas Image
Figure 2. MAD1L1 functions in spindle assembly checkpoint. (Upper panel) During mitosis, MAD1L1 binds to improperly attached kinetochrore, what results in recruitment and interaction with MAD2L1, and activation of the mitotic checkpoint complex (MCC). The MCC inhibits the anaphase-promoting complex/cyclosome (APC/C) and leads to cell cycle arrest. (Lower panel) In absence of unattached kinetochores, MAD1L1/MAD2L1 complex is not recruited, what results in chromosome segregation during anaphase. This figure was created using Servier Medical Art tools (


MAD1L1 belongs to the assembly control of the mitotic spindle, which acts as a component capable of blocking the onset of the anaphase if the chromosomes are not correctly aligned on the metaphase plate (Hardwick and Murray, 1995). The MAD1L1 protein has approximately 83 kDa and interacts with other proteins, such as MAD2L1, to perform its functions (Campbell et al., 2001; Wright et al., 2017). The complex MAD1L1/MAD2L1 binds to improperly attached kinetochrore, induces MAD1L1 phosphorylation by MPS1, and acts as an anchor for the formation of other protein interactions, including MAD2L1-CDC20 complex. The molecular events upon MAD1L1 and unattached kinetochores interaction lead to the formation of mitotic checkpoint complex (MCC), inhibition of anaphase-promoting complex/cyclosome (APC/C), and cell cycle arrest (Reviewed by Schuyler et al., 2012 and London and Biggins, 2014) (Figure 2).
Rodriguez-Bravo and colleagues (Rodriguez-Bravo et al., 2014) reported that the MAD1L1-MAD2L1 complex anchored to the nuclear pore complexes emits an inhibitory signal that limits the speed of the mitosis, facilitating corrections of possible errors, which would avoid a cell cycle arrest. Alterations in MAD1L1 are associated with chromosomal instability and aneuploidy (Avram et al., 2014; Tsukasaki et al., 2001).
Wan and colleagues (Wan et al., 2014) reported an elegant mechanistic study that described the non-related spindle assembly checkpoint and MAD2L1 independent functions for MADlL1. During interphase, MAD1L1 is localized in the Golgi apparatus, and participates in integrin secretion, adhesion, mobility, cell migration and PTK2 (FAK) signaling pathway (Wan et al., 2014).


MAD1L1 has a high homology among different species (Table 1).
Table 1. Comparative identity of human MAD1L1 with other species
% Identity for: Homo sapiens MAD1L1SymbolProteinDNA

vs. P. troglodytes


vs. M. mulatta


vs. C. lupus


vs. B. taurus


vs. M. musculus


vs. R. norvegicus


vs. G. gallus


vs. X. tropicalis


vs. D. rerio


vs. D. melanogaster


vs. A. gambiae





Recurrent mutations in the MAD1L1 gene are rare, and 153 missense substitution, 69 synonymous substitution, 8 nonsense substitution, 1 frameshift insertion and 8 frameshift deletion mutations are reported in COSMIC (Catalogue of Somatic Mutations in Cancer; Similar findings were reported in cBioPortal (, which includes 41824 cancer samples: somatic mutation frequency in MAD1L1 was 0.5% (195 mutations, being 166 missense and 29 truncating mutations). Analyzing together, mutation, amplification, deep deletion and multiple alterations, the total of cancer samples with any type of alteration was 570 (1.4%).

Implicated in

Entity name
Colorectal cancer
In HCT116 colorectal carcinoma cell line, MAD1L1 silencing disturbed the spindle checkpoint and leaded to aneuploidy (Kienitz et al., 2005). On the other hand, the induction of MAD1L1 overexpression resulted in aberrant mitotic timing, aneuploidy and resistance to apoptosis in DLD1 cells, a chromosomally stable colorectal cancer cell line (Ryan et al., 2012). The presence of the genotype His/His for the MAD1L1 Arg558His (rs1801368) polymorphism was associated with increased risk for colorectal cancer, using a dominant model, in a Chinese cohort (Zhong et al., 2015).
Entity name
Liver cancer
MAD1L1 expression was observed in 70% of new early diagnosed cases and 30% of recurrence hepatocellular carcinoma patients, suggesting that the loss of MAD1L1 may be involved in disease progression (Nam et al., 2008). MAD1L1 was found to be methylated in 50% of hepatocellular carcinoma cell lines and primary samples tested. Low MAD1L1 methylation was associated with increased tumor size and recurrence in hepatocellular carcinoma patients (Cui et al., 2016). Sze and colleagues (Sze et al., 2008) identified a novel splicing variant of MAD1L1, which was found overexpressed in 24% of hepatocellular carcinoma samples. Using functional studies, the authors showed that the ectopic expression of this novel splicing variant results mitotic checkpoint impairment and aneuploidy hematoma cell lines (Sze et al., 2008).
Entity name
Lung cancer
An initial screening for MAD1L1 mutations in 49 lung cancer patients found one sample with somatic mutation (T299A) and 1 sample with a possible germline mutation (R556H). Coe and colleagues (Coe et al., 2006) reported that the gain of a region on 7p22.3, including 350 Kbp fragment centered at MAD1L1, was observed in 13 out of 14 small-cell lung cancers (H187, H378, H889, H1607, H1672, H2107, H2141, H2171, HCC33, H82, H289, H524, H526, and H841) and in none of normal (BL289, BL1607, BL1672, BL2107, BL2141, and BL2171) cell lines analyzed. Using immunohistochemistry analysis, MAD1L1 positive expression was found to be higher in lymph node metastasis and primary tumor samples from small-cell lung cancer patients compared to adjacent non-cancerous tissue samples (Li et al., 2016). In small-cell lung cancer, the presence of MAD1L1 expression was associated with advanced stage of the disease, increased tumor size, higher incidence of lymph node metastasis and recurrence, and it was an independent predictor of poor survival outcomes (Li et al., 2016). In a cohort containing 1000 lung cancer patients and 1000 healthy donors, the genotype His/His for the MAD1L1 Arg558His (rs1801368) polymorphism was associated with lung cancer risk (Guo et al., 2010).
Entity name
Breast cancer
MAD1L1 was frequently higher expressed in tumor compared to non-malignant or normal breast cancer samples (Ryan et al., 2012; Yuan et al., 2006) and increased levels of MAD1L1 were associated with poor survival outcomes (Ryan et al., 2012). Conversely, high cytoplasm expression of MAD1L1 was observed in both, normal and breast cancer samples. However, nuclear MAD1L1 expression was significantly more frequent in breast cancer (28%) than normal (2%) samples (Sun et al., 2013). In the same study, the author also reported that nuclear MAD1L1 was associated with lower age onset, increased tumor size, higher tumor stage, presence of TP53 mutations and disease subtypes, and positive nuclear MAD1L1 was an independent predictor of worse clinical outcomes in breast cancer patients (Sun et al., 2013). In MCF-7, a breast cancer cell line, siRNA-mediate MAD1L1 silencing increased migration and reduced E-cadherin expression (Chen et al., 2012).
Entity name
Gastric cancer
Using proteomic approaches in primary samples of gastric carcinomas and its corresponding non-cancerous gastric mucosa, MAD1L1 was identified as lower expressed in gastric carcinoma samples (Nishigaki et al., 2005). Later, the same research group reported that MAD1L1 was downregulated in 47% of gastric adenomas and 60% of gastric carcinomas, and advanced carcinomas presented lower levels compared to early carcinomas (Osaki et al., 2007). In MKN-1, a gastric carcinoma cell line, ectopic MAD1L1 expression reduced proliferation and cell cycle progression (Osaki et al., 2007).
Entity name
Head and neck/oral cancer
Bhattacharjya and colleagues (Bhattacharjya et al., 2013) described a negative correlation between MAD1L1 and MIR125B, a miRNA associated with the suppression of malignant phenotype, in primary samples from head and neck/oral cancer patients. Recently, the t(5;7)(q34;p22) with fusion gene RARS /MAD1L1 was identified in 10% of nasopharyngeal carcinoma and head and neck cancer samples (Zhong et al., 2017). Functional studies indicated that RARS/MAD1L1 enhances cell proliferation, clonogenicity and tumorigenicity (Zhong et al., 2017).
Entity name
Kidney cancer
Using quantitative PCR, Pinto and colleagues (Pinto et al., 2007) reported that MAD1L1 is expressed at low levels in chromophobe renal cell carcinoma compared to normal kidney samples. The authors also reported that MAD1L1 mRNA levels are reduced in samples from clear cell kidney carcinoma compared to healthy donors (Pinto et al., 2008).
Entity name
Ovarian cancer
MAD1L1 mRNA levels were found to be downregulated in chemoresistant compared to chemosensitive epithelial ovarian tumors (Ju et al., 2009). Santibáñez and colleagues (Santibanez et al., 2013) reported that the genotype AA for the polymorphism MAD1L1 G1673A (rs1801368) was associated with advanced epithelial ovarian cancer risk and that the allele A was significantly associated with increased aneuploid cells in ovarian tumor samples. Functional studies indicate that the AA genotype is also associated with higher frequency of micronuclei and nondisjunction events (Santibanez et al., 2013).
Entity name
MAD1L1 gene expression was increased in grade IV gliomas compared to normal brain tissues (Bie et al., 2011).
Entity name
MAD1L1 is highly expressed in leukemia cell lines (Jurkat and K562) compared to normal peripheral blood mononuclear cells. In normal leukocytes, cell proliferation induction by PHA plus IL2 increased MAD1L1 expression (Iwanaga and Jeang, 2002).
Entity name
Using proteomics and transcriptomics approaches, MAD1L1 was higher expressed in follicular lymphoma - compared to mantle cell lymphoma -derived cell lines (Weinkauf et al., 2007) .
Entity name
Myeloproliferative neoplasm
Using whole-genome sequencing, Sloma and colleagues (Sloma et al., 2017) reported the presence of R270W heterozygous mutation in MAD1L1 gene in unusual case of BCR / ABL1 - and JAK2 V617F -positive chronic myeloid leukemia during chronic phase and accelerate phase. However, upon blast crisis evolution, the MAD1L1R270W mutation was found in homozygosis. The authors also reported the MAD1L1R270W mutation in an additional case of JAK2V617F -positive essential thrombocythemia (1 out of 101 myeloproliferative neoplasm cases tested) (Sloma et al., 2017).
Entity name
Prostate cancer
MAD1L1 heterozygous mutations were found in 2 out of 7 prostate cancer cell lines (LNCaP: MAD1L1R556C, and LPC4: MAD1L1R359Q) and 2 out of 33 (MAD1L1R59C and a stop codon at 318) primary samples from prostate carcinoma patients (Tsukasaki et al., 2001).
Entity name
Testicular germ cell tumor
Using a large cohort of testicular germ cell tumor and healthy donors, and genome-wide association study as approach, Chung and colleagues (Chung et al., 2013) identified that the SNP rs12699477 of MAD1L1 was associated with testicular germ cell tumor risk.


Pubmed IDLast YearTitleAuthors
247248942014Mitotic checkpoint proteins Mad1 and Mad2 - structural and functional relationship with implication in genetic diseases.Avram S et al
220224242011The accuracy of survival time prediction for patients with glioma is improved by measuring mitotic spindle checkpoint gene expression.Bie L et al
111811782001Mitotic checkpoint proteins HsMAD1 and HsMAD2 are associated with nuclear pore complexes in interphase.Campbell MS et al
122352892002Anaphase onset does not require the microtubule-dependent depletion of kinetochore and centromere-binding proteins.Canman JC et al
30998511987UDPgalactose:glucosylceramide beta 1----4-galactosyltransferase activity in human proximal tubular cells from normal and familial hypercholesterolemic homozygotes.Chatterjee S et al
220247682012The spindle checkpoint protein MAD1 regulates the expression of E-cadherin and prevents cell migration.Chen Y et al
236662392013Meta-analysis identifies four new loci associated with testicular germ cell tumor.Chung CC et al
161301252006Gain of a region on 7p22.3, containing MAD1L1, is the most frequent event in small-cell lung cancer cell lines.Coe BP et al
261387472016Genome-wide identification of differential methylation between primary and recurrent hepatocellular carcinomas.Cui C et al
205161472010Functional evaluation of missense variations in the human MAD1L1 and MAD2L1 genes and their impact on susceptibility to lung cancer.Guo Y et al
75931911995Mad1p, a phosphoprotein component of the spindle assembly checkpoint in budding yeast.Hardwick KG et al
172106952007Heterozygous deletion of mitotic arrest-deficient protein 1 (MAD1) increases the incidence of tumors in mice.Iwanaga Y et al
119806582002Expression of mitotic spindle checkpoint protein hsMAD1 correlates with cellular proliferation and is activated by a gain-of-function p53 mutant.Iwanaga Y et al
200668942009Identification of genes with differential expression in chemoresistant epithelial ovarian cancer using high-density oligonucleotide microarrays.Ju W et al
157821132005Partial downregulation of MAD1 causes spindle checkpoint inactivation and aneuploidy, but does not confer resistance towards taxol.Kienitz A et al
264999432016Mitotic arrest deficient-like 1 is correlated with poor prognosis in small-cell lung cancer after surgical resection.Li D et al
253031172014Signalling dynamics in the spindle checkpoint response.London N et al
184913692008Mitotic checkpoint gene MAD1 in hepatocellular carcinoma is associated with tumor recurrence after surgical resection.Nam CW et al
157973762005How do so few control so many?Nasmyth K et al
160038252005Proteomic identification of differentially-expressed genes in human gastric carcinomas.Nishigaki R et al
176740372007MAD1 (mitotic arrest deficiency 1) is a candidate for a tumor suppressor gene in human stomach.Osaki M et al
173332632007Expression changes of the MAD mitotic checkpoint gene family in renal cell carcinomas characterized by numerical chromosome changes.Pinto M et al
187912702008Overexpression of the mitotic checkpoint genes BUB1 and BUBR1 is associated with genomic complexity in clear cell kidney carcinomas.Pinto M et al
193721382009Enhanced genomic instabilities caused by deregulated microtubule dynamics and chromosome segregation: a perspective from genetic studies in mice.Rao CV et al
245814992014Nuclear pores protect genome integrity by assembling a premitotic and Mad1-dependent anaphase inhibitor.Rodriguez-Bravo V et al
227784092012Up-regulation of the mitotic checkpoint component Mad1 causes chromosomal instability and resistance to microtubule poisons.Ryan SD et al
234070472013The MAD1 1673 G → A polymorphism alters the function of the mitotic spindle assembly checkpoint and is associated with a worse response to induction chemotherapy and sensitivity to treatment in patients with advanced epithelial ovarian cancer.Santibáñez M et al
230935752012The Mad1-Mad2 balancing act--a damaged spindle checkpoint in chromosome instability and cancer.Schuyler SC et al
120065012002Crystal structure of the tetrameric Mad1-Mad2 core complex: implications of a 'safety belt' binding mechanism for the spindle checkpoint.Sironi L et al
286029462017Whole-genome analysis reveals unexpected dynamics of mutant subclone development in a patient with JAK2-V617F-positive chronic myeloid leukemia.Sloma I et al
238609282013Increased expression of mitotic arrest deficient-like 1 (MAD1L1) is associated with poor prognosis and insensitive to Taxol treatment in breast cancer.Sun Q et al
190108912008Role of a novel splice variant of mitotic arrest deficient 1 (MAD1), MAD1beta, in mitotic checkpoint control in liver cancer.Sze KM et al
114239792001Mutations in the mitotic check point gene, MAD1L1, in human cancers.Tsukasaki K et al
254479962014A Golgi-localized pool of the mitotic checkpoint component Mad1 controls integrin secretion and cell migration.Wan J et al
179902592007Proteome- and microarray-based expression analysis of lymphoma cell lines identifies a p53-centered cluster of differentially expressed proteins in mantle cell and follicular lymphoma.Weinkauf M et al
283464442017Genetic variants associated with mosaic Y chromosome loss highlight cell cycle genes and overlap with cancer susceptibility.Wright DJ et al
164284792006Increased expression of mitotic checkpoint genes in breast cancer cells with chromosomal instability.Yuan B et al
291335732018The RARS-MAD1L1 Fusion Gene Induces Cancer Stem Cell-like Properties and Therapeutic Resistance in Nasopharyngeal Carcinoma.Zhong Q et al
261831632015MAD1L1 Arg558His and MAD2L1 Leu84Met interaction with smoking increase the risk of colorectal cancer.Zhong R et al

Other Information

Locus ID:

NCBI: 8379
MIM: 602686
HGNC: 6762
Ensembl: ENSG00000002822


dbSNP: 8379
ClinVar: 8379
TCGA: ENSG00000002822


Gene IDTranscript IDUniprot

Expression (GTEx)



PathwaySourceExternal ID
Cell cycleKEGGko04110
Progesterone-mediated oocyte maturationKEGGko04914
Cell cycleKEGGhsa04110
Progesterone-mediated oocyte maturationKEGGhsa04914
Viral carcinogenesisKEGGhsa05203
Viral carcinogenesisKEGGko05203
Signal TransductionREACTOMER-HSA-162582
Signaling by Rho GTPasesREACTOMER-HSA-194315
RHO GTPase EffectorsREACTOMER-HSA-195258
RHO GTPases Activate ForminsREACTOMER-HSA-5663220
Cell CycleREACTOMER-HSA-1640170
Cell Cycle CheckpointsREACTOMER-HSA-69620
Mitotic Spindle CheckpointREACTOMER-HSA-69618
Amplification of signal from the kinetochoresREACTOMER-HSA-141424
Amplification of signal from unattached kinetochores via a MAD2 inhibitory signalREACTOMER-HSA-141444
Cell Cycle, MitoticREACTOMER-HSA-69278
Mitotic PrometaphaseREACTOMER-HSA-68877
Resolution of Sister Chromatid CohesionREACTOMER-HSA-2500257
Mitotic Metaphase and AnaphaseREACTOMER-HSA-2555396
Mitotic AnaphaseREACTOMER-HSA-68882
Separation of Sister ChromatidsREACTOMER-HSA-2467813

Protein levels (Protein atlas)

Not detected


Entity IDNameTypeEvidenceAssociationPKPDPMIDs
PA445204Ovarian NeoplasmsDiseaseClinicalAnnotationassociatedPD23407047


Pubmed IDYearTitleCitations
123517902002Role of Hec1 in spindle checkpoint signaling and kinetochore recruitment of Mad1/Mad2.186
206248992010Sustained Mps1 activity is required in mitosis to recruit O-Mad2 to the Mad1-C-Mad2 core complex.155
213940852011Constitutive Mad1 targeting to kinetochores uncouples checkpoint signalling from chromosome biorientation.81
189814712008Tpr directly binds to Mad1 and Mad2 and is important for the Mad1-Mad2-mediated mitotic spindle checkpoint.71
245814992014Nuclear pores protect genome integrity by assembling a premitotic and Mad1-dependent anaphase inhibitor.67
203796142010Personalized smoking cessation: interactions between nicotine dose, dependence and quit-success genotype score.62
183186012008Insights into mad2 regulation in the spindle checkpoint revealed by the crystal structure of the symmetric mad2 dimer.48
224932232012Structure of human Mad1 C-terminal domain reveals its involvement in kinetochore targeting.48
149780402004NEK2A interacts with MAD1 and possibly functions as a novel integrator of the spindle checkpoint signaling.43
280723882017A sequential multi-target Mps1 phosphorylation cascade promotes spindle checkpoint signaling.43


Keli Lima ; Joao Agostinho Machado-Neto

MAD1L1 (mitotic arrest deficient 1 like 1)

Atlas Genet Cytogenet Oncol Haematol. 2018-02-01

Online version: