Dataset Information

Cullin-RING ligases target substrates with geometrically optimized catalytic partners

ABSTRACT: Cullin-RING ubiquitin ligases (CRLs) control the degradation of a wide landscape of human proteins in combination with ubiquitin-carrying enzymes (UCEs). CRL expansion during evolution is apparent, with a few dozen in yeast that function with a single UCE and as many as 300 in humans that function with at least 8 UCEs. A major unaddressed question is why human CRL buildup has been accompanied by additional UCEs that function with CRLs. Here we demonstrate that human CRLs and UCEs can display specificity, resulting in increased affinity for each other and enhanced rates of ubiquitin transfer to substrates. To uncover the structural basis for CRL-UCE specificity, cryo-EM was performed on a CRL2 subfamily member with substrate receptor subunit FEM1C (CRL2FEM1C) in complex with a proxy for catalytically active UCE. The structure elucidated an extensive CRL-UCE interface that promotes proximity between the UCE active site and CRL2FEM1C-bound substrate. Unanticipated selectivity was also observed between the CRL substrate Lys ubiquitylation sites and the identity of the UCE. CRL-UCE specificity also manifests during targeted protein degradation by affecting the activities of drugs that induce ubiquitylation of neosubstrates. An emerging CRL code is revealed that drives selective formation of CRL-UCE complexes to promote rapid substrate ubiquitylation.

INSTRUMENT(S): Orbitrap Fusion Lumos, Orbitrap Exploris 480

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Barbara Steigenberger

LAB HEAD: Brenda A.

PROVIDER: PXD043523 | Pride | 2024-05-22

REPOSITORIES: Pride

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			Action	DRS
	20200111_Lum1_GK1_A10_KMR_OBJ0040919_QLPODIA.raw	Raw
	20200111_Lum1_GK1_A11_KMR_OBJ0040919_QLPODIA.raw	Raw
	20200111_Lum1_GK1_A12_KMR_OBJ0040919_QLPODIA.raw	Raw
	20200111_Lum1_GK1_A1_KMR_OBJ0040919_QLPODIA.raw	Raw
	20200111_Lum1_GK1_A2_KMR_OBJ0040919_QLPODIA.raw	Raw

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Publications

Cullin-RING ligases employ geometrically optimized catalytic partners for substrate targeting.

Li Jerry J Purser Nicholas N Liwocha Joanna J Scott Daniel C DC Byers Holly A HA Steigenberger Barbara B Hill Spencer S Tripathi-Giesgen Ishita I Hinkle Trent T Hansen Fynn M FM Prabu J Rajan JR Radhakrishnan Senthil K SK Kirkpatrick Donald S DS Reichermeier Kurt M KM Schulman Brenda A BA Kleiger Gary G

Molecular cell 20240220 7

Cullin-RING ligases (CRLs) ubiquitylate specific substrates selected from other cellular proteins. Substrate discrimination and ubiquitin transferase activity were thought to be strictly separated. Substrates are recognized by substrate receptors, such as Fbox or BCbox proteins. Meanwhile, CRLs employ assorted ubiquitin-carrying enzymes (UCEs, which are a collection of E2 and ARIH-family E3s) specialized for either initial substrate ubiquitylation (priming) or forging poly-ubiquitin chains. We d ...[more]

PMID: 38382526

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