Synthesis of Phosphatidylinositol 4,5-bisphosphate (PIP2) in Endosomal Compartments during Serum-Stimulated Cell Signaling
Open Access
Author:
Lee, Ellen
Area of Honors:
Biochemistry and Molecular Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Lorraine C Santy, Thesis Supervisor Song Tan, Thesis Honors Advisor
Keywords:
integrin recycling epithelial cell migration cancer endosomes
Abstract:
While epithelial cell migration facilitates normal processes such as wound repair and embryonic development, it can also underlie pathophysiological conditions like cancer metastasis. The ability of cells to become migratory relies on mechanisms involving turnover of focal adhesions and recycling of integrins through the cell’s endosomal system. Prior research suggests that a phospholipid, Phosphatidylinositol 4,5-bisphosphate (PIP2), binds proteins known to facilitate integrin recycling. Therefore, this study aimed to elucidate potential locations of PIP2 synthesis and localization during serum-stimulated integrin recycling. Assays conducted in HeLa cells, a cervical cancer cell line, were designed to decrease PIP2 levels at specific endosomal populations in the cell (EHD1, Rab11, Rab7, Rab5, and Rab8). DNA constructs for fluorescent proteins were utilized to quantify colocalization between integrins and endosomes as a measure of the extent of integrin recycling. The results suggest that Rab5 and EHD1 endosomes may be key locations of PIP2 synthesis and localization during serum-stimulated integrin recycling.