A novel function of Aft1 in regulating ferrioxamine B uptake: Aft1 modulates Arn3 ubiquitination in Saccharomyces cerevisiae.
Aft1 is a transcriptional activator in Saccharomyces cerevisiae that responds to iron availability and regulates the expression of genes in the iron regulon, such as FET3, FTR1 and the ARN family. Using a two-hybrid screen, we found that Aft1 physically interacts with the FOB (ferrioxamine B) transporter Arn3. This interaction modulates the ability of Arn3 to take up FOB. The interaction between Arn3 and Aft1 was confirmed by beta-galactosidase, co-immunoprecipitation and SPR (surface plasmon resonance) assays. Truncated Aft1 had a stronger interaction with Arn3 and caused a higher FOB-uptake activity than full-length Aft1. Interestingly, only full-length Aft1 induced the correct localization of Arn3 in response to FOB. Furthermore, we found Aft1 affected Arn3 ubiquitination. These results suggest that Aft1 interacts with Arn3 and may regulate the ubiquitination of Arn3 in the cytosolic compartment.
Jeong
Mi-Young
MY
School of Life Sciences and Biotechnology, Korea University Anam-Dong, Sungbuk-Gu, Seoul, Republic of Korea.
Kang
Chang-Min
CM
Kim
Ji-Hyun
JH
Heo
Dong-Hyuk
DH
Chang
Miwha
M
Baek
In-Joon
IJ
Ro
Hyeon-Su
HS
Choi
Il-Dong
ID
Kim
Tae-Hyoung
TH
Yun
Cheol-Won
CW
D002462:Cell Membrane / Q000378:metabolism; D002570:Ceruloplasmin / Q000378:metabolism; D003676:Deferoxamine / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D015203:Reproducibility of Results; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D020349:Surface Plasmon Resonance; D014157:Transcription Factors / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D054875:Ubiquitination
C090297:AFT1 protein, S cerevisiae; D005290:Ferric Compounds; D026901:Membrane Transport Proteins; C118510:SIT1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C002577:ferrioxamine B; D002570:Ceruloplasmin; C085513:FET3 protein, S cerevisiae; D003676:Deferoxamine; D008239:Lysine