Functional interaction of AIRE with PIAS1 in transcriptional regulation.
AIRE (autoimmune regulator) promotes the establishment of self-tolerance by regulating gene expression in the thymus. Mutations in AIRE lead to an autoimmune disease, APECED. Here we have identified PIAS proteins as novel AIRE interaction partners. Although PIAS proteins function as E3 SUMO ligases, AIRE is not sumoylated. We expressed AIRE, wt PIAS1, and PIAS1 mutants with deleted SP-RING domain or SUMO interaction motif (SIM) in different cell lines and demonstrate that AIRE and PIAS1 localize to adjacent nuclear bodies (NBs). The expression of AIRE enhances the formation of PIAS1 NBs. The ability of PIAS1 to localize into NBs and interconnect with AIRE is neither dependent on the SP-RING domain nor the SIM. Further, we show that PIAS1 is able to attract AIRE into SUMO1-containing complexes and that the process is dependent on the SIM of PIAS1. PIAS1 and AIRE concurrently activate the human insulin promoter, a known target gene of AIRE, and the SP-RING is required for this activation. Moreover, AIRE represses and PIAS1 activates the CSTB promoter, used as a model for a housekeeping promoter, and both the SP-RING and SIM are needed for its activation by PIAS1. Collectively, our data suggest that AIRE and PIAS1 interact functionally to regulate the activities of the target genes of AIRE.
Ilmarinen
Tanja
T
Department of Molecular Medicine, National Public Health Institute, Biomedicum Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland.
Kangas
Hannele
H
Kytömaa
Taina
T
Eskelin
Petra
P
Saharinen
Juha
J
Seeler
Jacob-S
JS
Tanhuanpää
Kimmo
K
Chan
Fiona Yih-Ling
FY
Slattery
Robyn Maree
RM
Alakurtti
Kirsi
K
Palvimo
Jorma J
JJ
Ulmanen
Ismo
I
D020816:Amino Acid Motifs; D000818:Animals; D002460:Cell Line; D055313:Cystatin B; D015891:Cystatins / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D007328:Insulin / Q000235:genetics; D051379:Mice; D050505:Mutant Proteins / Q000378:metabolism; D015530:Nuclear Matrix / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D050828:Protein Inhibitors of Activated STAT / Q000737:chemistry / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D017384:Sequence Deletion; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000235:genetics; D014162:Transfection; D000096927:AIRE Protein
D055313:Cystatin B; D015891:Cystatins; D007328:Insulin; D050505:Mutant Proteins; D050828:Protein Inhibitors of Activated STAT; D025841:Small Ubiquitin-Related Modifier Proteins; D014157:Transcription Factors; D000096927:AIRE Protein; C524994:CSTB protein, human; C524992:Cstb protein, mouse