| Structural highlights
Function
[MYLIP_HUMAN] E3 ubiquitin-protein ligase that mediates ubiquitination and subsequent proteasomal degradation of myosin regulatory light chain (MRLC), LDLR, VLDLR and LRP8. Activity depends on E2 enzymes of the UBE2D family. Proteasomal degradation of MRLC leads to inhibit neurite outgrowth in presence of NGF by counteracting the stabilization of MRLC by saposin-like protein (CNPY2/MSAP) and reducing CNPY2-stimulated neurite outgrowth. Acts as a sterol-dependent inhibitor of cellular cholesterol uptake by mediating ubiquitination and subsequent degradation of LDLR.[1] [2] [3] [4] [5] [6]
Publication Abstract from PubMed
We previously identified the E3 ubiquitin ligase IDOL as a sterol-dependent regulator of the LDL receptor (LDLR). The molecular pathway underlying IDOL action, however, remains to be determined. Here we report the identification and biochemical and structural characterization of an E2-E3 ubiquitin ligase complex for LDLR degradation. We identified the UBE2D family (UBE2D1-4) as E2 partners for IDOL that support both autoubiquitination and IDOL-dependent ubiquitination of the LDLR in a cell-free system. NMR chemical shift mapping and a 2.1 A crystal structure of the IDOL RING domain-UBE2D1 complex revealed key interactions between the dimeric IDOL protein and the E2 enzyme. Analysis of the IDOL-UBE2D1 interface also defined the stereochemical basis for the selectivity of IDOL for UBE2Ds over other E2 ligases. Structure-based mutations that inhibit IDOL dimerization or IDOL-UBE2D interaction block IDOL-dependent LDLR ubiquitination and degradation. Furthermore, expression of a dominant-negative UBE2D enzyme inhibits the ability of IDOL to degrade the LDLR in cells. These results identify the IDOL-UBE2D complex as an important determinant of LDLR activity, and provide insight into molecular mechanisms underlying the regulation of cholesterol uptake.
The IDOL-UBE2D complex mediates sterol-dependent degradation of the LDL receptor.,Zhang L, Fairall L, Goult BT, Calkin AC, Hong C, Millard CJ, Tontonoz P, Schwabe JW Genes Dev. 2011 Jun 15;25(12):1262-74. PMID:21685362[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Olsson PA, Korhonen L, Mercer EA, Lindholm D. MIR is a novel ERM-like protein that interacts with myosin regulatory light chain and inhibits neurite outgrowth. J Biol Chem. 1999 Dec 17;274(51):36288-92. PMID:10593918
- ↑ Bornhauser BC, Johansson C, Lindholm D. Functional activities and cellular localization of the ezrin, radixin, moesin (ERM) and RING zinc finger domains in MIR. FEBS Lett. 2003 Oct 9;553(1-2):195-9. PMID:14550572
- ↑ Bornhauser BC, Olsson PA, Lindholm D. MSAP is a novel MIR-interacting protein that enhances neurite outgrowth and increases myosin regulatory light chain. J Biol Chem. 2003 Sep 12;278(37):35412-20. Epub 2003 Jun 24. PMID:12826659 doi:10.1074/jbc.M306271200
- ↑ Zelcer N, Hong C, Boyadjian R, Tontonoz P. LXR regulates cholesterol uptake through Idol-dependent ubiquitination of the LDL receptor. Science. 2009 Jul 3;325(5936):100-4. doi: 10.1126/science.1168974. Epub 2009 Jun , 11. PMID:19520913 doi:10.1126/science.1168974
- ↑ Hong C, Duit S, Jalonen P, Out R, Scheer L, Sorrentino V, Boyadjian R, Rodenburg KW, Foley E, Korhonen L, Lindholm D, Nimpf J, van Berkel TJ, Tontonoz P, Zelcer N. The E3 ubiquitin ligase IDOL induces the degradation of the low density lipoprotein receptor family members VLDLR and ApoER2. J Biol Chem. 2010 Jun 25;285(26):19720-6. doi: 10.1074/jbc.M110.123729. Epub 2010, Apr 28. PMID:20427281 doi:10.1074/jbc.M110.123729
- ↑ Calkin AC, Goult BT, Zhang L, Fairall L, Hong C, Schwabe JW, Tontonoz P. FERM-dependent E3 ligase recognition is a conserved mechanism for targeted degradation of lipoprotein receptors. Proc Natl Acad Sci U S A. 2011 Dec 13;108(50):20107-12. doi:, 10.1073/pnas.1111589108. Epub 2011 Nov 22. PMID:22109552 doi:10.1073/pnas.1111589108
- ↑ Zhang L, Fairall L, Goult BT, Calkin AC, Hong C, Millard CJ, Tontonoz P, Schwabe JW. The IDOL-UBE2D complex mediates sterol-dependent degradation of the LDL receptor. Genes Dev. 2011 Jun 15;25(12):1262-74. PMID:21685362 doi:10.1101/gad.2056211
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