scholarly journals Unbiased Profiling of the Human Proinsulin Biosynthetic Interaction Network Reveals a Role for Peroxiredoxin 4 in Proinsulin Folding

Diabetes ◽  
2020 ◽  
Vol 69 (8) ◽  
pp. 1723-1734
Author(s):  
Duc T. Tran ◽  
Anita Pottekat ◽  
Saiful A. Mir ◽  
Salvatore Loguercio ◽  
Insook Jang ◽  
...  
2020 ◽  
Author(s):  
Ada Admin ◽  
Duc T. Tran ◽  
Anita Pottekat ◽  
Saiful A. Mir ◽  
Salvatore Loguercio ◽  
...  

The beta cell protein synthetic machinery is dedicated to the production of mature insulin, which requires the proper folding and trafficking of its precursor, proinsulin. The complete network of proteins that mediate proinsulin folding and advancement through the secretory pathway, however, remains poorly defined. Here we used affinity purification and mass spectrometry to identify for the first time, the proinsulin biosynthetic interaction network in human islets. Stringent analysis established a central node of proinsulin interactions with ER folding factors, including chaperones and oxidoreductases, that is remarkably conserved in both sexes and across three ethnicities. The ER-localized peroxiredoxin PRDX4 was identified as a prominent proinsulin interacting protein. In beta cells, gene silencing of PRDX4 rendered proinsulin susceptible to misfolding, particularly in response to oxidative stress, while exogenous PRDX4 improved proinsulin folding. Moreover, proinsulin misfolding induced by oxidative stress or high glucose was accompanied by sulfonylation of PRDX4, a modification known to inactivate peroxiredoxins. Notably, islets from patients with Type II diabetes (T2D) exhibited significantly higher levels of sulfonylated PRDX4 than islets from healthy individuals. In conclusion, we have generated the first reference map of the human proinsulin interactome to identify critical factors controlling insulin biosynthesis, beta cell function, and T2D.


2020 ◽  
Author(s):  
Ada Admin ◽  
Duc T. Tran ◽  
Anita Pottekat ◽  
Saiful A. Mir ◽  
Salvatore Loguercio ◽  
...  

The beta cell protein synthetic machinery is dedicated to the production of mature insulin, which requires the proper folding and trafficking of its precursor, proinsulin. The complete network of proteins that mediate proinsulin folding and advancement through the secretory pathway, however, remains poorly defined. Here we used affinity purification and mass spectrometry to identify for the first time, the proinsulin biosynthetic interaction network in human islets. Stringent analysis established a central node of proinsulin interactions with ER folding factors, including chaperones and oxidoreductases, that is remarkably conserved in both sexes and across three ethnicities. The ER-localized peroxiredoxin PRDX4 was identified as a prominent proinsulin interacting protein. In beta cells, gene silencing of PRDX4 rendered proinsulin susceptible to misfolding, particularly in response to oxidative stress, while exogenous PRDX4 improved proinsulin folding. Moreover, proinsulin misfolding induced by oxidative stress or high glucose was accompanied by sulfonylation of PRDX4, a modification known to inactivate peroxiredoxins. Notably, islets from patients with Type II diabetes (T2D) exhibited significantly higher levels of sulfonylated PRDX4 than islets from healthy individuals. In conclusion, we have generated the first reference map of the human proinsulin interactome to identify critical factors controlling insulin biosynthesis, beta cell function, and T2D.


Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 47-OR
Author(s):  
DUC T. TRAN ◽  
PETER ARVAN ◽  
RANDAL J. KAUFMAN ◽  
PAMELA ITKIN-ANSARI

Diabetes ◽  
1988 ◽  
Vol 37 (3) ◽  
pp. 276-280 ◽  
Author(s):  
S. E. Fineberg ◽  
M. J. Rathbun ◽  
S. Hufferd ◽  
N. S. Fineberg ◽  
C. T. Spradlin ◽  
...  
Keyword(s):  

Diabetes ◽  
1985 ◽  
Vol 34 (1) ◽  
pp. 84-91 ◽  
Author(s):  
R. M. Cohen ◽  
T. Nakabayashi ◽  
P. M. Blix ◽  
P. A. Rue ◽  
S. E. Shoelson ◽  
...  
Keyword(s):  

Diabetes ◽  
1997 ◽  
Vol 46 (6) ◽  
pp. 978-982 ◽  
Author(s):  
J. E. Kaufmann ◽  
J. C. Irminger ◽  
J. Mungall ◽  
P. A. Halban
Keyword(s):  

2020 ◽  
Author(s):  
Jessica Mow ◽  
Arti Gandhi ◽  
Daniel Fulford

Decreased social functioning and high levels of loneliness and social isolation are common in schizophrenia spectrum disorders (SSD), contributing to reduced quality of life. One key contributor to social impairment is low social motivation, which may stem from aberrant neural processing of socially rewarding or punishing stimuli. To summarize research on the neurobiology of social motivation in SSD, we performed a systematic literature review of neuroimaging studies involving the presentation of social stimuli intended to elicit feelings of reward and/or punishment. Across 11 studies meeting criteria, people with SSD demonstrated weaker modulation of brain activity in regions within a proposed social interaction network, including prefrontal, cingulate, and striatal regions, as well as the amygdala and insula. Firm conclusions regarding neural differences in SSD in these regions, as well as connections within networks, are limited due to conceptual and methodological inconsistencies across the available studies. We conclude by making recommendations for the study of social reward and punishment processing in SSD in future research.


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