Potential role of novel PDZK1 adaptor protein in adipocyte development and lipid metabolism.

• Main Author: Hong, ZhongCheng.
• Other Authors: School of Biological Sciences
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Biological sciences
• Online Access: http://hdl.handle.net/10356/44744
• Institution: Nanyang Technological University

Research on adipogenesis has garnered great interest as adipose tissue was identified to possess endocrinal activities, other than just a depot for fats storage. We have identified a novel PSD-95/Dlg/ZO-1 domain containing 1 (PDZK1) adaptor protein in adipocyte that was downregulated when the lipodystrophic gene, Seipin, was mutated. PDZK1 role in adipocyte was unknown and we sought to elucidate its expression and regulatory function during adipogenesis. PDZK1 expression in 3T3-L1 cells was observed to be highly upregulated in late differentiation and was tightly dependent on adipocyte differentiation, similar to the expression pattern of key adipogenic regulators. This suggests a potential novel role for PDZK1 in regulating late stage adipocyte differentiation. PDZK1 reported receptor target gene in liver, Scavenger Receptor Class B Type I (SR-BI), was also highly upregulated during late differentiation in adipocyte. This strengthened our hypothesis that they may together regulate terminal adipocyte differentiation. SR-BI and key pro-adipogenic regulators such as CCAAT/Enhancer Binding Protein-α, Peroxisome Proliferator-Activated Receptors-γ and Sterol Response Element-Binding-Protein 1c were not downregulated, when PDZK1 was knock-down by short-hairpin RNA. Whether PDZK1 act upstream or downstream of these pro-adipogenic factors requires further test as our control cells did not differentiate well to provide an accurate comparison.