Prolyl 4-hydroxylase, transmembrane is a protein that in humans is encoded by the P4HTM gene.

The product of this gene belongs to the family of prolyl 4-hydroxylases. This protein is a prolyl hydroxylase that may be involved in the degradation of hypoxia-inducible transcription factors under normoxia. It plays a role in adaptation to hypoxia and may be related to cellular oxygen sensing. Alternatively spliced variants encoding different isoforms have been identified.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.