Aggregation chaperones enhance aggregation and storage of secretory proteins in endocrine cells

Renu K. Jain, Paul B.M. Joyce, Sven Ulrik Gorr

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Calcium-induced aggregation has been proposed to play a role in the sorting and storage of secretory proteins in secretory granules of endocrine cells. The regulation of this process is not known. Hexahistidine epitope tags were used to create aggregation chaperones that enhance the calcium-induced aggregation of secretory granule proteins in vitro. Indeed, 100% recovery of the aggregating target protein was achieved without any modification of the target protein. The aggregation chaperone is not trapped in the aggregates. Co-expression of His6-tagged secreted alkaline phosphatase and the regulated secretory protein chromogranin A resulted in an increased chromogranin storage in secretory granules, and stimulated secretion of chromogranin A increased 50%. However, secretion of secreted alkaline phosphatase was not affected by the hexahistidine epitope tag. Thus, calcium-induced aggregation is not a passive process; rather, aggregation and sorting of secretory proteins can be regulated by aggregation chaperones in the secretory pathway of endocrine cells.

Original languageEnglish (US)
Pages (from-to)27032-27036
Number of pages5
JournalJournal of Biological Chemistry
Volume275
Issue number35
DOIs
StatePublished - Sep 1 2000

Fingerprint

Dive into the research topics of 'Aggregation chaperones enhance aggregation and storage of secretory proteins in endocrine cells'. Together they form a unique fingerprint.

Cite this