Digitized Honors Theses (2002-2017)

Date of Award

5-2014

Document Type

Undergraduate Thesis

Degree Name

BS

Department

Biomedical Sciences

Faculty Mentor

Donna Cioffi, Ph.D., Audrey Vasauskas, Ph.D.

Advisor(s)

Michael Spector, Ph.D., P. Thulasiraman, Ph.D.

Abstract

Endothelial cells line blood vessels and allow for the selective transport of molecules. Disruption of this barrier leads to increased permeability resulting in pathologies such as acute lung injury. Store operated calcium entry (SOCE), specifically through the calcium selective channel, Isco, leads to increased lung endothelial cell disruption and permeability. Isoc activation/inactivation may be regulated through the post-translational modification, namely phosphorylation and via the addition of O-linked B-N-acetylglucosamine (O-GlcNAcylation). O-GlcNAcylation can have an inverse relationship with phosphorylation on the same serine or threonine residues. Proteins associated with the Isoc include the canonical transient receptor potential proteins 1 and 4 (TRPC-1,4), Orail, and STIM1. In this study, we sought to determine whether STIM1 has the O-GlcNAc modification and whether the degree of this modification changes upon SOCE activation. Immunoprecipitation and immunoblot analyses show that STIM1 is O-GlcNAcylated. Western blot analyses also show that STIM1 O-GlcNAcylation decreases as SOCE is activated. Immunohistochemical staining also indicates the presence of O-GlcNAc in whole rat lung sectins. However, immunocytochemical studies investigating the co-localization of STIM1 and O-GlcNAc are inconclusive due to the abundance of O-GlcNAc in PAECs, and staining conditons must be further optimized. Taken together, these results suggest that O-GlcNAcylation of STIM1 regulates SOCE in PAECs, and this regulation may be reciprocal with STIM1 phosphorylation. However, further experimentation is needed to confirm this reciprocal relationship and the co-localization of STIM1 and O-GlcNAc upon SOCE activation.

Comments

© 2014 Payal Patel, ALL RIGHTS RESERVED

Download

Share

COinS