Compartment:
nucleoplasm,
cytosol
The POU5F1 (OCT4) gene is transcribed to yield mRNA and the mRNA is translated to yield protein (Rao et al. 2004, Richards et al. 2004, Cauffman et al. 2005, Tai et al. 2005, Gerrard et al. 2005, Li et al. 2006, Adewumi et al. 2007,Assou etal. 2007). POU5F1 mRNA and protein are found in the cytoplasm of oocytes and cleavage-stage embryos (Cauffman et al. 2005). POU5F1 protein becomes nuclear during compaction, and protein and mRNA are present in inner cell mass and trophectoderm (Cauffman et al. 2005). Transcripts are also detectable in some differentiated tissues (Cauffman et al. 2005). POU5F1 is expressed in adult stem cells and cancers (Tai et al. 2005). POU5F1, SOX2, NANOG, SALL4, and SF-1(NR5A1) bind the promoter of the POU5F1 gene and enhance transcription (Matin et al. 2004, Chew et al. 2005, Boyer et al. 2005, Babaie et al. 2007, Greber et al. 2007, Wang et al. 2007, Yang et al. 2010, Chia et al. 2010). POU5F1 and SOX2 bind adjacent sites at the promoter and form a heterodimer on the DNA. SALL4 binds the promoter of the POU5F1 gene and activates transcription of POU5F1 (Yang et al. 2010). POU5F1 activates SALL4 expression thus forming a self-reinforcing loop. Activation-induced cytidine deaminase (AID) binds the methylated promoter of the POU5F1 gene, demethylates it, and enhances expression of POU5F1 (Bhutani et al. 2009). Hypoxia acts via HIF3A and EPAS1 (HIF2A) to enhance expression of POU5F1 (Forristal et al. 2010). LIN28 binds the POU5F1 mRNA and increases translation (Qiu et al. 2009).