Neddylation mediates ventricular chamber maturation through repression of Hippo signaling

Abstract

During development, ventricular chamber maturation is a crucial step in the formation of a functionally competent postnatal heart. Defects in this process can lead to left ventricular noncompaction cardiomyopathy and heart failure. However, molecular mechanisms underlying ventricular chamber development remain incompletely understood. Neddylation is a posttranslational modification that attaches ubiquitin-like protein NEDD8 to protein targets via NEDD8-specific E1-E2-E3 enzymes. Here, we report that neddylation is temporally regulated in the heart and plays a key role in cardiac development. Cardiomyocyte-specific knockout of NAE1, a subunit of the E1 neddylation activating enzyme, significantly decreased neddylated proteins in the heart. Mice lacking NAE1 developed myocardial hypoplasia, ventricular noncompaction, and heart failure at late gestation, which led to perinatal lethality. NAE1 deletion resulted in dysregulation of cell cycle-regulatory genes and blockade of cardiomyocyte proliferation in vivo and in vitro, which was accompanied by the accumulation of the Hippo kinases Mst1 and LATS1/2 and the inactivation of the YAP pathway. Furthermore, reactivation of YAP signaling in NAE1-inactivated cardiomyocytes restored cell proliferation, and YAP-deficient hearts displayed a noncompaction phenotype, supporting an important role of Hippo-YAP signaling in NAE1-depleted hearts. Mechanistically, we found that neddylation regulates Mst1 and LATS2 degradation and that Cullin 7, a NEDD8 substrate, acts as the ubiquitin ligase of Mst1 to enable YAP signaling and cardiomyocyte proliferation. Together, these findings demonstrate a role for neddylation in heart development and, more specifically, in the maturation of ventricular chambers and also identify the NEDD8 substrate Cullin 7 as a regulator of Hippo-YAP signaling.

The functional analysis of Cullin 7 E3 ubiquitin ligases in cancer

“…However, whether F-box proteins mediate the degradation of rEag1 has not been reported. In addition, CUL7 participates in Mst1 ubiquitination to induce YAP signaling and cardiomyocyte proliferation 29 . Wang et al identified a signaling pathway controlling cell migration and placental development involved in the progression of 3-M dwarfism.…”

“…Five cellular proteins have been previously recognized as substrates of the CUL7 E3 ligase: cyclin D1 16 , insulin receptor substrate (IRS-1) 22 , hematopoietic progenitor kinase 1 (HPK1) 23 , Golgi reassembly-stacking protein 65 (GRASP65) 24 , and TBC1 domain family member 31 (TBC1D31) 25 . Recently, additional proteins have been implicated in the degradative process of the CUL7 E3 Ub ligase: histone H2B-like (H2B) 26 , Mof4 family associated protein 1 (MRFAP1) 27 , AID 20 , caspase-8 28 , macrophage stimulating 1 (Mst1) 29 , and pleckstrin homology like domain family B member 2 (LL5β) 30 . Interestingly, several proteins, such as p53 12 , 31 , 32 , SV40 T antigen 33 – 35 , glomulin (GLMN) 36 , PARC 37 , 38 , obscurin-like 1 (OBSL1), and coiled-coil domain containing 8 (CCDC8) 39 , have been shown to interact with CUL7, but this interaction does not affect their stability, suggesting that the CUL7 E3 ligase may perform a proteolytic function and also play a non-proteolytic role.…”

Transient inhibition of neddylation at neonatal stage evokes reversible cardiomyopathy and predisposes the heart to isoproterenol-induced heart failure

“…We (46) recently identified an essential role for neddylation in cardiac development and maturation. We demonstrated that neddylation is highly active in embryonic and fetal hearts but is developmentally downregulated in adult hearts.…”

The function and regulation of OTU deubiquitinases

“…They also show Poly-SUMOylation is required for OTUB2 to interact with and deubiquitinate YAP/TAZ [49]. Since, Zou et al shows NEDD8 substrate Cul7 acts as a ubiquitin ligase to promote Mst1 degradation, thereby activating YAP signaling and cardiomyocyte proliferation [58]. All these imply OTUB2 may function in cardiac morphogenesis.…”