Faculty Collaboration Database

Identifying the crucial binding domain of histatin-1 to recombinant TMEM97 in activating chemotactic migration in human corneal epithelial cells. Biochem Biophys Res Commun 2024 Dec 20;739:150991

Date

11/16/2024

Pubmed ID

39547121

Pubmed Central ID

PMC12138758

DOI

10.1016/j.bbrc.2024.150991

Scopus ID

2-s2.0-85208761843 (requires institutional sign-in at Scopus site)   7 Citations

Abstract

TMEM97, also known as the sigma-2 receptor, plays a crucial role as an endoplasmic reticular protein involved in various physiological processes such as wound healing, and cholesterol metabolism. Moreover, TMEM97 has been implicated in multiple human diseases including neurodegenerative disorders and cancers. Histatin peptides are endogenous peptides with diverse biological effects, including antimicrobial, immunomodulatory, and wound healing functions. Recent studies have revealed that histatin-1 (Hst1) acts as an endogenous ligand for TMEM97 and is essential for Hst1-induced corneal epithelial migration. In this study, we sought to establish the crucial Hst1 residues that facilitate binding to TMEM97. The purified full-length (FL)-TMEM97 expressed from Escherichia coli exhibited comparable binding affinity, as indicated by the dissociation equilibrium constant (K_D) determined by Surface plasmon resonance (SPR), to commercially sourced TMEM97 expressed in mammalian cells. SPR analysis revealed that TMEM97 bound to FL-Hst1 and selected deletion mutants of Hst1. Truncation experiments pinpointed the central region of Hst1 as crucial for its binding to TMEM97, with the loss of residues 15-19 either significantly weakening or completely abolishing the binding interaction. Furthermore, alanine substitution mutant experiments highlighted residues 9-19 as critical for the interaction between TMEM97 and Hst1. Functional assays including migration and signaling were also compared for Hst1 and mutant Hst1. Collectively, these findings underscore the specific binding of Hst1 to TMEM97 and elucidate the critical regions within Hst1 necessary for this interaction which is critically important for the epithelial migration and signaling changes in the ERK and Akt pathways.

Author List

Son KN, Lee H, Lee SM, Pierre-Jacques D, Shah D, Cologna SM, Aakalu VK

Author

Vinay Kumar Aakalu MPH, MD Chair, Professor in the Ophthalmology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Binding Sites
Chemotaxis
Epithelial Cells
Epithelium, Corneal
Histatins
Humans
Membrane Proteins
Protein Binding
Protein Domains
Recombinant Proteins