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#SCF complex

3 public questions tagged with this topic.

Cell Cycle Regulation

The SCF complex plays a crucial role in:

SCF complex, acronym for SKP1-CUL1-F-box protein, represents prototypical cullin-RING ubiquitin ligase family controlling G1/S transition through regulated proteolysis of CDK inhibitors. Core scaffold comprises elongated Cullin1 linking adaptor SKP1 and RING domain protein Rbx1 that recruits E2 ubiquitin-conjugating enzyme. Substrate specificity arises from interchangeable F-box proteins containing leucine-rich repeats or WD40 domains that bind phosphorylated degrons. In budding yeast, F-box Cdc4 recognizes Sic1 inhibitor after phosphorylation by Cln-CDK1 at multiple CDK consensus sites, while

Ref: Morgan, The Cell Cycle: Principles of Control, 2nd ed., Chapter 5: SCF Ligases and CDK Inhibitors.

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Cell Cycle Regulation

The SCF complex is primarily responsible for:

SCF complex forms prototypical cullin-RING ubiquitin ligase governing G1/S and S-phase progression, distinct from mitotic APC/C. Architecture comprises scaffold Cullin1, adaptor Skp1, RING finger Rbx1 recruiting E2 ubiquitin conjugating enzyme, and interchangeable F-box protein providing substrate specificity through WD40 or leucine-rich repeats. Activity regulated by substrate phosphorylation creating phosphodegron that interacts with F-box. During late G1, Cdk2-Cyclin E phosphorylates cyclin-dependent kinase inhibitor p27 Kip1 at Thr187, Sic1 ortholog in yeast at multiple CDK sites and p21 a

Ref: Cardozo & Pagano, SCF Ubiquitin Ligases Regulate Cell Cycle, Nat Rev Mol Cell Biol 2004; Frescas & Pagano, SCF Functions in G1/S Control.

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Cell Cycle Regulation

What is the function of the SCF complex?

Ordered progression through interphase depends on timely degradation of regulatory proteins via ubiquitination. The SCF complex, meaning Skp1-Cullin-F-box, is a modular cullin-RING E3 ligase active from late G1 to early M. Core components include scaffold Cullin1, adaptor Skp1, RING finger Rbx1 and interchangeable F-box protein conferring substrate specificity. Canonical function involves CDK inhibitor p27 Kip1. When Cyclin E-CDK2 phosphorylates p27 at Thr187, phosphodegron is recognized by F-box protein Skp2 together with accessory Cks1, leading to Lys48-linked polyubiquitination and proteaso

Ref: Cardozo & Pagano, SCF Ubiquitin Ligases and Cell Cycle Control, Nat Rev Mol Cell Biol 2004; NCBI, SCF Functions.

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