XXXX -inducible factor 3 biology: Complexities and emerging themes.

@entity7738 @entity519 @entity26 @entity19249
UNASSIGNED: The @entity519 -inducible factor (HIF) family has three distinct members in most vertebrates. All three HIFs consist of a unique and @entity26 -labile a subunit and a common and stable b subunit. While @entity7738 and HIF-2 function as master regulators of the transcriptional response to @entity519 , much less is known about HIF-3. The @entity19249 gene gives rise to multiple @entity19249 variants due to the utilization of different promoters, different transcription initiation sites, and alternative splicing. These @entity19249 variants are expressed in different tissues, at different developmental stages, and that they are differentially regulated by @entity519 and other factors. Recent studies suggest that different @entity19249 variants have different and even opposite functions. There is strong evidence that full-length @entity19249 protein functions as an @entity26 -regulated transcription activator and it activates a unique transcriptional program in response to @entity519 . Many @entity19249 target genes have been identified. While some short @entity19249 variants act as dominant negative regulators of @entity7738 /2a actions, other @entity19249 variants can inhibit @entity7738 /2a actions by competing for the common HIF-b. There are also a number of @entity19249 variants yet to be explored. Future studies of these naturally occurring @entity19249 variants will provide new and important insights into HIF biology and may lead to the development of new therapeutic strategies.
