Work

Inhibitory PAS Domain Protein (IPAS) Is a Hypoxia-inducible Splicing Variant of the Hypoxia-inducible Factor-3α Locus

Year: 2002

Type: article

Abstract: The inhibitory PAS (Per/Arnt/Sim) domain protein, IPAS, functions as a dominant negative regulator of hypoxia-inducible transcription factors (HIFs) by forming complexes with those proteins that fail to bind to hypoxia response elements of target genes. We have previously observed that IPAS is predominantly expressed in mice in Purkinje cells of the cerebellum and in corneal epithelium of the eye where it appears to play a role in negative regulation of angiogenesis and maintenance of an avascular phenotype. Sequencing of the mouse IPAS genomic structure revealed that IPAS is a splicing variant of the HIF-3alpha locus. Thus, in addition to three unique exons (1a, 4a, and 16) IPAS shares three exons (2, 4, and 5) with HIF-3alpha as well as alternatively spliced variants of exons 3 and 6. In experiments using normal mice and mice exposed to hypoxia (6% O(2)) for 6 h we observed alternative splicing of the HIF-3alpha transcript in the heart and lung. The alternatively spliced transcript was only observed under hypoxic conditions, thus defining a novel mechanism of hypoxia-dependent regulation of gene expression. Importantly, this mechanism may establish negative feedback loop regulation of adaptive responses to hypoxia/ischemia in these tissues.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.c200328200

Authors: Yuichi Makino, Arvydas Kanopka, William J. Wilson, Hirotoshi Tanaka, Lorenz Poellinger

Institutions: Karolinska Institutet, Institute of Medical Science, The University of Tokyo, The University of Tokyo

Language: English

Topic: Cancer, Hypoxia, and Metabolism

Subfield: Cancer Research

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,430