IBRI RESEARCH PUBLISHED: Hypusine biosynthesis in ß cells links polyamine metabolism to facultative cellular proliferation to maintain glucose homeostasis

12/3/2019

Senior Scientist Teresa Mastracci was part of a team of researchers led by Raghu Mirmira at UChicago who found that hypusine biosynthesis is necessary to maintain glucose balance

Deoxyhypusine synthase (DHPS) uses the polyamine spermidine to catalyze the hypusine modification of the mRNA translation factor eIF5A and promotes oncogenesis through poorly defined mechanisms. Because germline deletion of Dhps is embryonically lethal, its role in normal postnatal cellular function in vivo remains unknown. We generated a mouse model that enabled the inducible, postnatal deletion of Dhps specifically in postnatal islet β cells, which function to maintain glucose homeostasis. Removal of Dhps did not have an effect under normal physiologic conditions. However, upon development of insulin resistance, which induces β cell proliferation, Dhps deletion caused alterations in proteins required for mRNA translation and protein secretion, reduced production of the cell cycle molecule cyclin D2, impaired β cell proliferation, and induced overt diabetes. We found that hypusine biosynthesis was downstream of protein kinase C-ζ and was required for c-Myc–induced proliferation. Our studies reveal a requirement for DHPS in β cells to link polyamines to mRNA translation to effect facultative cellular proliferation and glucose homeostasis.

To read the complete research article, go to Science Signaling.

2019 Annual Report cover

The IBRI 2019 Annual Report is now available. The report theme is “Catalyze, Complement, Connect,” which correlates with the IBRI's goals to seek solutions for health problems, enhance the Indiana life sciences ecosystem, and expedite solutions for the most pressing health issues.