F-box proteins and protein degradation: an emerging theme in cellular regulation

• Published in: Plant molecular biology 2000-09, Vol.44 (2), p.123-128
• Main Authors: del Pozo, J C, Estelle, M
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; cullin; F-box proteins; Gene Expression Regulation, Plant; jasmonic acid; Molecular Sequence Data; Peptide Synthases - genetics; Peptide Synthases - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; proteosomes; Sequence Homology, Amino Acid; SKP Cullin F-Box Protein Ligases
• ISSN: 0167-4412
• DOI: 10.1023/A:1006413007456

Selective protein degradation by the ubiquitin-proteosome pathway has recently emerged as a powerful regulatory mechanism in a wide variety of cellular processes. Ubiquitin conjugation requires the sequential activity of three enzymes or protein complexes called the ubiquitin-activating enzyme (E1), the ubiquitin-conjugating enzyme (E2), and the ubiquitin-protein ligase (E3). In most eukaryotes, there are a small number of similar E1 isoforms without apparent functional specificity. The specific selection of target proteins is accomplished by the E2 and E3 proteins. One of the best-characterized families of E3s are the SCF complexes. The SCF is composed of a cullin (Cdc53), SKP1, RBX1 and one member of a large family of proteins called F-box proteins. The function of the F-box protein is to interact with target proteins. In some cases, the stability of the F-box protein may regulate activity of the SCF complex. In addition, post-translational modification of the cullin subunit by the ubiquitin-like protein RUB/NEDD8 appears to regulate SCF function. In plants, the SCF has so far been implicated in floral development, circadian clock, and response to the plant growth regulators auxin and jasmonic acid.