Background:　NEDL2　is　a　member　of　the　HECT　type　ubiquitin　ligase　NEDD4　family,　but　its　function　remains　largely　unknown.　Results:　NEDL2　is　degraded　by　APC/C-Cdh1　during　mitotic　exit　and　regulates　metaphase　to　anaphase　transition.　Conclusion:　NEDL2　appears　to　dynamically　modulate　regulation　of　mitosis.　Significance:　Our　data　provide　a　novel　substrate　of　APC/C-Cdh1　and　reveal　an　additional　protein　by　which　HECT　type　ubiquitin　ligase　can　regulate　mitosis.　NEDD4-like　ubiquitin　ligase　2　(NEDL2)　is　a　HECT　type　ubiquitin　ligase.　NEDL2　enhances　p73　transcriptional　activity　and　degrades　ATR　kinase　in　lamin　misexpressed　cells.　Compared　with　the　important　functions　of　other　HECT　type　ubiquitin　ligase,　there　is　less　study　concerning　the　function　and　regulation　of　NEDL2.　Using　primary　antibody　immunoprecipitation　and　mass　spectrometry,　we　identify　a　list　of　potential　proteins　that　are　putative　NEDL2-interacting　proteins.　The　candidate　list　contains　many　of　mitotic　proteins,　especially　including　several　subunits　of　anaphase-promoting　complex/cyclosome　(APC/C)　and　Cdh1,　an　activator　of　APC/C.　Cdh1　can　interact　with　NEDL2　in　vivo　and　in　vitro.　Cdh1　recognizes　one　of　the　NEDL2　destruction　boxes　(R(740)GSL(743))　and　targets　it　for　degradation　in　an　APC/C-dependent　manner　during　mitotic　exit.　Overexpression　of　Cdh1　reduces　the　protein　level　of　NEDL2,　whereas　knockdown　of　Cdh1　increases　the　protein　level　of　NEDL2　but　has　no　effect　on　the　NEDL2　mRNA　level.　NEDL2　associates　with　mitotic　spindles,　and　its　protein　level　reaches　a　maximum　in　mitosis.　The　function　of　NEDL2　during　mitosis　is　essential　because　NEDL2　depletion　prolongs　metaphase,　and　overexpression　of　NEDL2　induces　chromosomal　lagging.　Elevated　expression　of　NEDL2　protein　and　mRNA　are　both　found　in　colon　cancer　and　cervix　cancer.　We　conclude　that　NEDL2　is　a　novel　substrate　of　APC/C-Cdh1　as　cells　exit　mitosis　and　functions　as　a　regulator　of　the　metaphase　to　anaphase　transition.　Its　overexpression　may　contribute　to　tumorigenesis.