Homeobox Protein NANOG - Function

Function

NANOG is a gene expressed in embryonic stem cells (ESCs) and is thought to be a key factor in maintaining pluripotency. NANOG is thought to function in concert with other factors such as POU5F1 and SOX2 to establish ESC identity. These cells offer an important area of study because of their ability to maintain pluripotency. In other words, these cells have the ability to become virtually any cell of any of the three germ layers (endoderm, ectoderm, mesoderm). It is for this reason that understanding the mechanisms that maintain a cell's pluripotency is critical for researchers to understand how stem cells work; and may lead to future advances in treating degenerative diseases.

Analysis of arrested embryos demonstrated that embryos express pluripotency marker genes such as POU5F1, NANOG and Rex1. Derived human ESC lines also expressed specific pluripotency markers:

• TRA-1-60
• TRA-1-81
• SSEA4
• alkaline phosphatase
• TERT
• Rex1

These markers allowed for the differentiation in vitro and in vivo conditions into derivatives of all three germ layers.

POU5F1, TDGF1 (CRIPTO), SALL4, LECT1, and BUB1 are also related genes all responsible for self-renewal and pluripotent differentiation.

The NANOG protein has been found to be a transcriptional activator for the Rex1 promoter, playing a key role in sustaining Rex1 expression. Knockdown of NANOG in embryonic stem cells results in a reduction of Rex1 expression, while forced expression of NANOG stimulates Rex1 expression.