Shaping Up Mitochondrion in Motion

Abstract

We previously reported that hair follicle dermal papilla cells (HFDPCs) show two types of
mitochondria, which are filamentous (untangled) and rounded (tangled) mitochondria. Plateletderived
growth factor-AA (PDGF-AA) shifts the population balance toward the filamentous
type that produces more adenosine triphosphate (ATP) than the other. In addition, the cells
show filamentous mitochondria during the process of cellular migration. Furthermore, here
we demonstrated that an inner membrane protein, optic atrophy 1 (OPA1), is involved in the
filamentous-rounded transition of the organelle. We suggest that OPA1 confers longitudinal
rigidity on the filamentous mitochondria. Other cells such as breast cancer cells utilize small
fragmented mitochondria, instead of a filamentous form, in the migration process. Regarding
the apparent inconsistency with those other reports on the morphological change upon the onset
of cellular migration, we discuss communal feature of the regulation of mitochondrial morphology
in different cellular systems: all previous reports showed that the organelle become slender
or smaller in the energy-demanding activity.