F-box linker domain
PfamPF00646
Pfam clanCL0271
InterproIPR001810
SmartSM00256
PrositePS50181
Scop1fs2
Membranome superfamily630

F-box proteins, sometimes abbreviated as FBX,[1][2] are proteins containing at least one F-box domain. The first identified F-box protein is one of three components of the SCF complex, which mediates ubiquitination of proteins targeted for degradation by the 26S proteasome.

Core components

F-box domain is a protein structural motif of about 50 amino acids that mediates protein–protein interactions. It has consensus sequence and varies in few positions. It was first identified in cyclin F.[3] The F-box motif of Skp2, consisting of three alpha-helices, interacts directly with the SCF protein Skp1.[3] F-box domains commonly exist in proteins in cancer with other protein–protein interaction motifs such as leucine-rich repeats (illustrated in the Figure) and WD repeats, which are thought to mediate interactions with SCF substrates.[4]

Function

F-box proteins have also been associated with cellular functions such as signal transduction and regulation of the cell cycle.[5] In plants, many F-box proteins are represented in gene networks broadly regulated by microRNA-mediated gene silencing via RNA interference.[6] F-box proteins are involved in many plant vegetative and reproduction growth and development. For example, F-box protein-FOA1 involved in abscisic acid (ABA) signaling to affect the seed germination.[7] ACRE189/ACIF1 can regulate cell death and defense when the pathogen is recognized in the Tobacco and Tomato plant.[8]

In human cells, under high-iron conditions, two iron atoms stabilise the F-Box FBXL5 and then the complex mediates the ubiquitination of IRP2.[9]

Regulation

F-box protein levels can be regulated by different mechanisms. The regulation can occur via protein degradation process and association with SCF complex . For example, in yeast, the F-box protein Met30 can be ubiquitinated in a cullin-dependent manner.[10]

References

  1. ^ Hua, Zhihua; Zou, Cheng; Shiu, Shin-Han; Vierstra, Richard D. (2011-01-28). "Phylogenetic Comparison of F-Box (FBX) Gene Superfamily within the Plant Kingdom Reveals Divergent Evolutionary Histories Indicative of Genomic Drift". PLOS ONE. 6 (1). Bibcode:2011PLoSO...616219H. doi:10.1371/journal.pone.0016219. ISSN 1932-6203. PMC 3030570. PMID 21297981
  2. ^ Kuroda, Hirofumi; Yanagawa, Yuki; Takahashi, Naoki; Horii, Yoko; Matsui, Minami (2012-11-15). "A Comprehensive Analysis of Interaction and Localization of Arabidopsis SKP1-LIKE (ASK) and F-Box (FBX) Proteins". PLOS ONE. 7 (11). Bibcode:2012PLoSO...750009K. doi:10.1371/journal.pone.0050009. ISSN 1932-6203. PMC 3499479. PMID 23166809
  3. ^ Bai C, Sen P, Hofmann K, Ma L, Goebl M, Harper JW, Elledge SJ (1996). "SKP1 connects cell cycle regulators to the ubiquitin proteolysis machinery through a novel motif, the F-box". Cell. 86 (2): 263–274. doi:10.1016/S0092-8674(00)80098-7. PMID 8706131
  4. ^ Kipreos ET, Pagano M (2000). "The F-box protein family". Genome Biol.. 1 (5). doi:10.1186/gb-2000-1-5-reviews3002. PMC 138887. PMID 11178263
  5. ^ Craig KL, Tyers M (1999). "The F-box: a new motif for ubiquitin dependent proteolysis in cell cycle regulation and signal transduction". Prog. Biophys. Mol. Biol.. 72 (3): 299–328. doi:10.1016/S0079-6107(99)00010-3. PMID 10581972
  6. ^ Jones-Rhoades MW, Bartel DP, Bartel B (2006). "MicroRNAS and their regulatory roles in plants". Annu Rev Plant Biol. 57 (1): 19–53. Bibcode:2006AnRPB..57...19J. doi:10.1146/annurev.arplant.57.032905.105218. PMID 16669754
  7. ^ Peng J, Yu D, Wang L, Xie M, Yuan C, Wang Y, Tang D, Zhao X, Liu X (2012). "Arabidopsis F-box gene FOA1 involved in ABA signaling". Science China Life Sciences. 55 (6): 497–506. doi:10.1007/s11427-012-4332-9. PMID 22744179
  8. ^ Ha VD, Tsitsigiannis DI, Rowland O, Lo J, Rallapalli G, Maclean D, Takken FL, Jones JD (2008). "The F-box protein ACRE189/ACIF1 regulates cell death and defense responses activated during pathogen recognition in tobacco and tomato". Plant Cell. 20 (3): 697–719. Bibcode:2008PlanC..20..697V. doi:10.1105/tpc.107.056978. PMC 2329923. PMID 18375657
  9. ^ Moroishi T, Nishiyama M, Takeda Y, Iwai K, Nakayama KI (2011). "The FBXL5-IRP2 axis is integral to control of iron metabolism in vivo". Cell Metabolism. 14 (3): 339–351. doi:10.1016/j.cmet.2011.07.011. PMID 21907140
  10. ^ Kaiser P, Su NY, Yen JL, Ouni I, Flick K (2006). "The yeast ubiquitin ligase SCFMet30: connecting environmental and intracellular conditions to cell division". Cell Division. 1: 16. doi:10.1186/1747-1028-1-16. PMC 1579207. PMID 16895602

Further reading