A Chemical Biology Study of Human Pluripotent Stem Cells Unveils HSPA8 as a Key Regulator of Pluripotency

Summary

Chemical biology methods such as high-throughput screening (HTS) and affinity-based target identification can be used to probe biological systems on a biomacromolecule level, providing valuable insights into the molecular mechanisms of those systems. Here, by establishing a human embryonal carcinoma cell-based HTS platform, we screened 171,077 small molecules for regulators of pluripotency and identified a small molecule, Displurigen, that potently disrupts hESC pluripotency by targeting heat shock 70-kDa protein 8 (HSPA8), the constitutively expressed member of the 70-kDa heat shock protein family, as elucidated using affinity-based target identification techniques and confirmed by loss-of-function and gain-of-function assays. We demonstrated that HSPA8 maintains pluripotency by binding to the master pluripotency regulator OCT4 and facilitating its DNA-binding activity.

Highlights

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  A human ECC-based screen identified novel chemical regulators of pluripotency

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  Displurigen disrupts human embryonic stem cell pluripotency by targeting HSPA8

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  HSPA8 maintains pluripotency by facilitating the DNA-binding activity of OCT4

Abstract

Geng and colleagues describe the identification of Displurigen, a small molecule regulator of human embryonic stem cell pluripotency, through high-throughput screening. Heat shock protein HSPA8 was identified to be the biological target of Displurigen and was shown to maintain pluripotency by binding to and facilitating the DNA-binding activity of OCT4.