PHD3-SUMO conjugation represses HIF1 transcriptional activity independently of PHD3 catalytic activity.
By controlling HIFα hydroxylation and stability, the prolyl hydroxylase domain (PHD)-containing proteins are essential to the maintenance of oxygen homeostasis; therefore these enzymes are tightly regulated. Small ubiquitin-like modifier (SUMO) is a 10-kDa protein readily conjugated to lysine residues of the targeted proteins in a process termed SUMOylation. In this study, we introduce SUMO conjugation as a novel regulator of PHD3 (also known as EGLN3). PHD3 SUMOylation occurs at a cluster of four lysines at the C-terminal end of the protein. Furthermore, PHD3 SUMOylation by SUMO2 or SUMO3 contributes to PHD3-mediated repression of HIF1-dependent transcriptional activity. Interestingly, PHD3-SUMO conjugation does not affect PHD3 hydroxylase activity or HIF1α stability, providing new evidence for a dual role of PHD3 in HIF1 regulation. Moreover, we show that hypoxia modulates PHD3-SUMO conjugation and that this modification inversely correlates with HIF1 activation. PHD3 SUMOylation highlights a new and additional layer of regulation that is likely required to fine-tune HIF function.
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain.
Analía
A
Núñez-O'Mara
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain.
Almudena
A
Gerpe-Pita
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain.
Sara
S
Pozo
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain.
Onintza
O
Carlevaris
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain.
Bakarne
B
Urzelai
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain.
Fernando
F
Lopitz-Otsoa
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain.
Manuel S
MS
Rodríguez
Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain eberra@cicbiogune.es.
Edurne
E
Berra
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases / Q000235:genetics / Q000378:metabolism*; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism*; D058207:Sumoylation / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism*
C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C117909:SUMO2 protein, human; C492189:SUMO3 protein, human; D025841:Small Ubiquitin-Related Modifier Proteins; D014452:Ubiquitins; C488894:EGLN3 protein, human; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases
EGLN; HIFα; Hypoxia; PHD; SUMO; Transcriptional repression