# CRISPR Screen to Identify Novel Secreted Epidermal Regulators

> **NIH NIH R03** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2020 · $78,750

## Abstract

PROJECT SUMMARY
 The epidermis consists of distinct cell layers that work in concert to execute a wide variety of essential
functions. Keratinocytes comprise the majority of the cells of the epidermis, and form distinct strata from the
basal proliferative layer to the outermost cornified layer. Keratinocytes of all strata secrete a variety of
protein factors that have critical roles in the proper function of the epidermis, including structural proteins,
antimicrobial peptides, proteases and protease inhibitors, and cell-cell signaling molecules. Despite the
recognized role of extracellular proteins in epidermal homeostasis, a comprehensive evaluation of these
secreted factors—the keratinocyte “secretome”— has not been performed.
 This proposal describes the comprehensive catalog of secreted epidermal proteins we have identified
by mass spectrometry. Analysis of the secretome of progenitor and differentiated keratinocytes reveals
>100 novel factors whose function in the epidermis is unknown. Studying them one-by-one or through a
candidate approach would be a time and resource-intensive effort.
 Here, we propose to use a CRISPR/Cas9-based genetic screen to systematically identify the functional
keratinocyte secreted proteins that impact epidermal renewal and differentiation. This effort would
accelerate our understanding of the function of secreted proteins in the skin, and we pave the way to
identify new skin biomarkers and therapeutics.
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## Key facts

- **NIH application ID:** 9968103
- **Project number:** 5R03AR075844-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Bryan Sun
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $78,750
- **Award type:** 5
- **Project period:** 2019-07-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9968103

## Citation

> US National Institutes of Health, RePORTER application 9968103, CRISPR Screen to Identify Novel Secreted Epidermal Regulators (5R03AR075844-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9968103. Licensed CC0.

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