Högskolan i Skövde

Lipids serve numerous different processes in biological cell communication. As for the case ofPhosphatidylinositol‐(4,5)‐biphosphate (PIP2), which serves actin‐dynamics, endocytosis, and ofrecent importance, exocytosis. PIP2 proceeds these functions at the cell's plasma membrane, whichyields the possibility to also exist at the membrane of large dense‐core vesicles. With the lipidsfunctions previously known, what factor does PIP2 serve if located on the membrane? This studyintends to use confocal imaging and vesicle impact electrochemical cytometry to study the locationand function respectably of the lipid membrane. Analysis was carried out on both PC12 cells as cell lineand bovine chromaffin as primary cells for each respective analysis. Phospholipase C delta‐1 (PLCδ1)markers were used in the microscopy experiments. The external application of PIP2 on extracted largedense‐core vesicles (LDCV) experimentally was performed. This study observed the location of PIP2 isindeed on large dense‐core vesicles well apart from the plasma membrane. In the extracted largedense‐core vesicles which was used a model to study how the changes in PIP2 levels affect fusion,increasing PIP2 levels significantly reduced the half‐time of LDCV. Indicating that PIP2 effect is on themembrane stability, resulting in rapid breakup of LDCV membrane. Which is probably resulted byaffecting membrane order from clustering PIP2. These findings broaden our understanding of the lipidPIP2, as it also lay way for future research, among cell‐to‐cell communication, vesicles, and hormonaltreatment. It also indicates the useability of combining imaging and amperometric for observationalstudies.