title: Polarized and Stage-Dependent Distribution of Immunoreactivity for Novel PDZ-Binding Protein Preso1 in Adult Neurogenic Regions.
abstract: BACKGROUND
  Adult neural stem cells have the potential for self-renewal and differentiation into multiple cell lineages via symmetric or asymmetric cell division. Preso1 is a recently identified protein involved in the formation of dendritic spines and the promotion of axonal growth in developing neurons. Preso1 can also bind to cell polarity proteins, suggesting a potential role for Preso1 in asymmetric cell division.
  
  
  METHODS
  To investigate the distribution of Preso1, we performed immunohistochemistry with adult mouse brain slice. Also, polarized distribution of Preso1 was assessed by immunocytochemistry in cultured neural stem cells.
  
  
  RESULTS
  Immunoreactivity for Preso1 (Preso1-IR) was strong in the rostral migratory stream and subventricular zone, where proliferating transit-amplifying cells and neuroblasts are prevalent. In cultured neural stem cells, Preso1-IR was unequally distributed in the cell cytosol. We also observed the distribution of Preso1 in the subgranular zone of the hippocampal dentate gyrus, another neurogenic region in the adult brain. Interestingly, Preso1-IR was transiently observed in the nuclei of doublecortin-expressing neuroblasts immediately after asymmetric cell division.
  
  
  CONCLUSIONS
  Our study demonstrated that Preso1 is asymmetrically distributed in the cytosol and nuclei of neural stem/progenitor cells in the adult brain, and may play a significant role in cell differentiation via association with cell polarity machinery.
authors.affiliation: Department of Anatomy, BK21 Program, Korea University College of Medicine, Seoul, Korea.
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Department of Anatomy, BK21 Program, Korea University College of Medicine, Seoul, Korea.
authors.forename: Woon Ryoung
authors.initials: WR
authors.lastname: Kim
authors.affiliation: Department of Emergency Medical Technology, Kyungil University College of Nursing and Public Health, Gyeongsan, Korea.
authors.forename: Younghwa
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Anatomy, BK21 Program, Korea University College of Medicine, Seoul, Korea.
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Lee
authors.affiliation: Department of Anatomy, BK21 Program, Korea University College of Medicine, Seoul, Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Anatomy, BK21 Program, Korea University College of Medicine, Seoul, Korea.
authors.forename: Woong
authors.initials: W
authors.lastname: Sun
keywords: Adult neural stem cells; Cell polarity; Dentate gyrus; Frmpd4; Preso1; Subventricular zone