TY - JOUR
T1 - A novel C53/LZAP-interacting protein regulates stability of C53/LZAP and DDRGK domain-containing protein 1 (DDRGK1) and modulates NF-κB signaling
AU - Wu, Jianchun
AU - Lei, Guohua
AU - Mei, Mei
AU - Tang, Yi
AU - Li, Honglin
PY - 2010/5/14
Y1 - 2010/5/14
N2 - C53/LZAP (also named as Cdk5rap3) is a putative tumor suppressor that plays important roles in multiple cell signaling pathways, including DNA damage response and NF-κB signaling. Yet how its function is regulated remains largely unclear. Here we report the isolation and characterization of two novel C53/LZAP-interacting proteins, RCAD (Regulator of C53/LZAP and DDRGK1) and DDRGK1 (DDRGK domain-containing protein 1). Our co-immunoprecipitation assays confirmed their interactions, while gel filtration assay indicated that C53/LZAP and RCAD may form a large protein complex. Intriguingly, we found that RCAD knockdown led to dramatic reduction of C53/LZAP and DDRGK1 proteins. We also found that C53/LZAP and DDRGK1 became more susceptible to the proteasome-mediated degradation in RCAD knockdown cells, whereas their ubiquitination was significantly attenuated by RCAD overexpression. In addition, we found that RCAD, like C53/LZAP, also plays an important role in regulation of NF-κB signaling and cell invasion. Taken together, our findings strongly suggest that RCAD is a novel regulator of C53/LZAP tumor suppressor and NF-κB signaling.
AB - C53/LZAP (also named as Cdk5rap3) is a putative tumor suppressor that plays important roles in multiple cell signaling pathways, including DNA damage response and NF-κB signaling. Yet how its function is regulated remains largely unclear. Here we report the isolation and characterization of two novel C53/LZAP-interacting proteins, RCAD (Regulator of C53/LZAP and DDRGK1) and DDRGK1 (DDRGK domain-containing protein 1). Our co-immunoprecipitation assays confirmed their interactions, while gel filtration assay indicated that C53/LZAP and RCAD may form a large protein complex. Intriguingly, we found that RCAD knockdown led to dramatic reduction of C53/LZAP and DDRGK1 proteins. We also found that C53/LZAP and DDRGK1 became more susceptible to the proteasome-mediated degradation in RCAD knockdown cells, whereas their ubiquitination was significantly attenuated by RCAD overexpression. In addition, we found that RCAD, like C53/LZAP, also plays an important role in regulation of NF-κB signaling and cell invasion. Taken together, our findings strongly suggest that RCAD is a novel regulator of C53/LZAP tumor suppressor and NF-κB signaling.
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U2 - 10.1074/jbc.M110.110619
DO - 10.1074/jbc.M110.110619
M3 - Article
C2 - 20228063
AN - SCOPUS:77952034227
SN - 0021-9258
VL - 285
SP - 15126
EP - 15136
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 20
ER -