# Osiris Genes as Novel Coordinators of Protein Trafficking in Drosophila Trachea

> **NIH NIH R15** · OAKLAND UNIVERSITY · 2021 · $438,957

## Abstract

Summary
 Biological tubes with appropriate sizes are critical for the proper functioning of most major human organ
systems (including but not limited to kidneys, lungs, and blood vessels). Malformation of tubes leads to various
human diseases, such as polycystic kidney disease and vascular diseases. Drosophila trachea is the premier
system to study the fundamental mechanisms underlying tubular organ formation.
 The Drosophila trachea is a ramifying network of epithelial tubes with a monolayer of epithelial cells
surrounding an apical lumen. During tube expansion, the apical secretion burst deposits large amounts of
luminal matrix components to the apical extracellular lumen. This process is critical for tube expansion to
acquire mature sizes. Previous studies on apical secretion focused on the identification of components of the
vesicular trafficking pathway involved in this process. As expected, in addition to endoplasmic reticulum and
Golgi, a few endosomes are also required in this process. Instead of identifying additional trafficking
components, the objective of this project is to reveal the “broader coordination” of various trafficking
components during apical secretion. This is a previously underappreciated mechanism in apical secretion in
Drosophila trachea as well as in the overall field of vesicular trafficking.
 Our preliminary study on a poorly understood Osiris (Osi) gene family strongly indicates that Osi family
genes function as “traffic coordinators” to direct post-Golgi protein trafficking. In addition, a recent homology
search revealed that Osi genes share noticeable sequence homology to glyoxalase 1 (Glo-1). Glo-1 is well
known for its function in detoxification of methylglyoxal, a metabolic byproduct of glycolysis. It has been
reported that Glo-1 plays a role in vesicular trafficking as well as morphological changes in blood vessels.
These discoveries lead to a plausible hypothesis that they may also have some functional overlap in tubular
organs. Our central hypothesis is that Osi genes function as “traffic coordinators” to direct apical proteins by
coordinated changes within secretion-related (e.g. endosomes, exosomes) and degradation-related trafficking
components (e.g. lysosomes, autophagosomes). We will test this hypothesis by completing the following three
specific aims: Aim. 1 Determine the function of Osi genes in apical secretion of the apical luminal matrix during
tube expansion. Aim. 2: Determine the function of Osi genes as coordinators to increase numbers, volumes,
activities of secretion-related trafficking components at the expense of degradation-related trafficking
components in trachea. Aim. 3: Identify proteins that directly bind to Osi proteins.
 This project is significant because understanding the “broader coordination” between various trafficking
components will fill the gap in our understanding of the regulatory hierarchy in protein trafficking.

## Key facts

- **NIH application ID:** 10291609
- **Project number:** 1R15GM140376-01A1
- **Recipient organization:** OAKLAND UNIVERSITY
- **Principal Investigator:** Lan Jiang
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $438,957
- **Award type:** 1
- **Project period:** 2021-07-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10291609

## Citation

> US National Institutes of Health, RePORTER application 10291609, Osiris Genes as Novel Coordinators of Protein Trafficking in Drosophila Trachea (1R15GM140376-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10291609. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*