Asymmetric localization of LGN but not AGS3, two homologs of Drosophila pins, in dividing human neural progenitor cells.
Human neural progenitor cells (hNPCs) can be recovered from postmortem human brains and used to study the molecular basis of neurogenesis. Human NPCs are being used to investigate the molecular basis of cell fate determination during stem cell divisions, based on comparison with the Drosophila model system. Drosophila neuroblasts and sensory organ precursors undergo well-defined asymmetric cell divisions (ACD), under the control of a genetically defined set of apical and basal determinants that are localized tightly and dynamically during division. We show by indirect immunofluorescence, confocal microscopy, and time-lapse video-microscopy that LGN and AGS3, two human homologs of the Drosophila ACD determinant Pins, have distinct patterns of localization in hNPCs. When cells are grown under conditions favoring proliferation, LGN is distributed asymmetrically in a cell cycle-dependent manner; it localizes to one side of the dividing cell and segregates into one of the daughter cells. When the cells are grown under conditions favoring differentiation, LGN accumulates in double foci similar to those containing the mitotic apparatus protein NuMA, and in a pattern shown previously for LGN and NuMA in differentiated cells. AGS3, a slightly more distant Pins homolog than LGN, does not show asymmetric localization in these cells. The progenitor cell marker nestin also localizes asymmetrically in colcemid-treated hNPCs and colocalizes with LGN. The results suggest that hNPCs undergo ACD and that similar molecular pathways may underlie these divisions in Drosophila and human cells.
Developmental Biology Center, University of California, Irvine, California 92697, USA. pjbryant@uci.edu
Tannin J
TJ
Fuja
Philip H
PH
Schwartz
Dan
D
Darcy
Peter J
PJ
Bryant
D000818:Animals; D034961:Antigens, Nuclear; D001921:Brain / Q000166:cytology; D002352:Carrier Proteins / Q000378:metabolism*; D002452:Cell Count; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D018797:Cell Cycle Proteins / Q000737:chemistry*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D003703:Demecolcine / Q000494:pharmacology; D004330:Drosophila; D029721:Drosophila Proteins / Q000737:chemistry*; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007381:Intermediate Filament Proteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D018613:Microscopy, Confocal / Q000379:methods; D009419:Nerve Tissue Proteins; D064231:Nestin; D009474:Neurons / Q000378:metabolism*; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism*; D040681:Structural Homology, Protein; D013997:Time Factors; D014162:Transfection / Q000379:methods; D014404:Tubulin / Q000378:metabolism; D014742:Videodisc Recording / Q000379:methods
D034961:Antigens, Nuclear; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; C102754:GPSM2 protein, human; D007381:Intermediate Filament Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins; C577484:NES protein, human; C050045:NUMA1 protein, human; D009419:Nerve Tissue Proteins; D064231:Nestin; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; C405164:Pins protein, Drosophila; D014404:Tubulin; D049452:Green Fluorescent Proteins; D004247:DNA; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D003703:Demecolcine