Squamous cell carcinoma–related oncogene (SCCRO) neddylates Cul3 protein to selectively promote midbody localization and activity of Cul3KLHL21 protein complex during abscission

Abstract

Squamous cell carcinoma-related oncogene (SCCRO)/DCUN1D1, a component of the neddylation E3 complex, regulates the activity of the cullin-RING-ligase type of ubiquitination E3s by promoting neddylation of cullin family members. Studies have shown that SCCRO regulates proliferation and Here we show that inactivation of SCCRO results in prolonged mitotic time because of delayed and/or failed abscission. The effects of SCCRO on abscission involve its role in neddylation and localization of Cul3 to the midbody. The Cul3 adaptor KLHL21 mediates the effects of SCCRO on abscission, as it fails to localize to the midbody in SCCRO-deficient cells during abscission, and its inactivation resulted in phenotypic changes identical to SCCRO inactivation. Ubiquitination-promoted turnover of Aurora B at the midbody was deficient in SCCRO- and KLHL21-deficient cells, suggesting that it is the target of Cul3 at the midbody. Correction of abscission delays in SCCRO-deficient cells with addition of an Aurora B inhibitor at the midbody stage suggests that Aurora B is the target of SCCRO-promoted Cul3 activity. The activity of other Cul3-anchored complexes, including Cul3, was intact in SCCRO-deficient cells, suggesting that SCCRO selectively, rather than collectively, neddylates cullins Combined, these findings support a model in which the SCCRO, substrate, and substrate adaptors cooperatively provide tight control of neddylation and cullin-RING-ligase activity.

Inhibition of neddylation induces mitotic defects and alters MKLP1 accumulation at the midbody during cytokinesis

“…The most likely cullins to be regulated by neddylation at the cleavage furrow and midbody are CUL1 and 3, both of which have been identified as components of the midbody [38][39][40][41]. The mitotic defects seen in our study after treatment of mitotic cells with MLN4924, including binucleated cells and failed cytokinesis, are also reminiscent of the effects of siRNA knock-down of CUL3 in human cells and in C. elegans [11,38], and siRNA knockdown of the neddylation complex component DCUN1D1/ SCCRO [51]. AURKB, which regulates mitotic progression by phosphorylating a number of substrates involved in mitotic progression including MKLP1 [6], is also a substrate of CUL1 and CUL3 [38,39], and potentially could have altered stability with MLN4924 treatment.…”

“…In asynchronous cells, AURKB levels do not appear to be affected by 4-h treatment with 1 μM MLN4924, more than 3 times the dose used in this study [52]. However, a recent study by Huang et al, (2017) [51] indicates AURKB stability in mitosis can be affected by inhibition of neddylation. In this study knock-down of DCUN1D1/SCCRO, which promotes CUL3 activation and localization at the cleavage furrow, stabilized AURKB levels in mitotic cells, delaying the completion of cytokinesis [51].…”

“…However, a recent study by Huang et al, (2017) [51] indicates AURKB stability in mitosis can be affected by inhibition of neddylation. In this study knock-down of DCUN1D1/SCCRO, which promotes CUL3 activation and localization at the cleavage furrow, stabilized AURKB levels in mitotic cells, delaying the completion of cytokinesis [51]. Another candidate protein involved in cytokinesis that is also a substrate of CUL3 is KATNA1 (also known p60/Katanin in mammals and MEI-1 in C. elegans), which localizes to the mitotic spindle during mitosis and is responsible for severing microtubules [11,53].…”

The Cis-Regulatory Code for Kelch-like 21/30 Specific Expression in Ciona robusta Sensory Organs

“…Klhl21 is known to bind E3 ubiquitin ligase through Cul3 (Maerki et al, 2009;Courtheoux et al, 2016) and Klhl30 has been identified as a circadian pathway gene involved in the onset of glioma (Madden et al, 2014). Like many other Klhl members, Klhl21 is implicated in diverse types of carcinoma, probably due to its role in cell division (Shi et al, 2016;Huang et al, 2017;Chen et al, 2018). Our findings represent the first expression data for Klhl21/30 subfamily in the chordate nervous system.…”

Functional analysis of Cullin 3 E3 ligases in tumorigenesis

“…Increased expression [147] Aurora B [145,279] KLHL22 Mutation [294] PLK1 [280] KLHL42 Increased expression [148] p60 [149] KLHL18 NA Aurora A [150] KBTBD2 NA p85α [153] IBTKα NA PDCD4 [155] Cheng et al Page 45 Table 6 Summary of evidence for context-dependent neoplastic role of Cullin 3-based E3 ligases. [186,220,295] BRD2/3/4, HDAC6, INF2, DAXX [189,218,239,295] KCTD2 NA Either increased or decreased expression [75,159] c-Myc [75] BTBD34 (TNFAIP1) NA Mutation or overexpression [160,161] RhoA [290] ZBTB16 (PLZF) NA Either increased or decreased expression [162,163] Atgl4L [293] KBTBD7 NA NA TIAM1, Neurofibromin [131,288] KBTBD8 NA NA TCOF1, NOLC1 [289] Table 7 Functional summary of SPOP in mammalian systems.…”