Drp1 function and mechanism in mammalian cells have been extensively studied, and multiple attempts were carried out for a better understanding of the enzymatic activity of the protein and its mechanism in mitochondrial fission. Additionally, the involvement of Drp1 in several diseases and its interaction with pathological intermediates associated with mitochondrial fission dysfunction raised many questions concerning the development of diseases. However, the exact molecular mechanism behind these interactions and the molecular function of Drp1 remains incompletely covered. In the present study, we investigated a specific site of Drp1 protein in the first domain responsible for the GTPase activity and its expected function and mutational consequences under the normal condition on the mitochondrial dynamics. The induced Ser39Ala mutation has initially exhibited highly fused mitochondria. We transfected SH-SY5Y cells with a sitedirected mutated construct of Drp1 protein and investigated the observed changes in mitochondrial morphology. Statistical analysis revealed increased mitochondrial fusion of shDrp1 S39A cells. The disclosed involvement of this site in the GTPase activity, hence mitochondrial dynamics, may contribute to a better understanding of the protein’s functional domain and its role in neurodegenerative diseases, and perhaps explore therapeutical approaches.