Transient nuclear localization of Fyn kinase during development in zebrafish.
Fyn protein tyrosine kinase is present in the unfertilized and fertilized egg, becomes activated within minutes following fertilization, and has been localized to the cortical cytoplasm and spindle apparatus of the zygote. In order to establish the expression pattern of Fyn in the early embryo, we examined the distribution pattern of Fyn by immunofluorescence microscopy. Fyn protein is distributed evenly among cells of the cleavage stage zebrafish embryo and is concentrated in the cortical region of each cell. During blastula and gastrula stages, Fyn was expressed in all cells, however a subpopulation of cells exhibited strong nuclear staining for Fyn. Nuclear Fyn staining was not observed after the gastrula period of development, nor in the adult zebrafish. Immunoprecipitation of Fyn from isolated mid-blastula nuclei confirmed Fyn was present in the nucleus. This is, to our knowledge, the first demonstration of Fyn kinase, which lacks a nuclear localization signal, present in the nucleus. The transient compartmentalization of Fyn in the nucleus could be important in nuclear signaling.
Rongish
B J
BJ
Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
Kinsey
W H
WH
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D000936:Antigen-Antibody Complex / Q000032:analysis; D001692:Biological Transport / Q000502:physiology; D002467:Cell Nucleus / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology; D004625:Embryo, Nonmammalian / Q000201:enzymology; D005775:Gastrula / Q000201:enzymology; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D051076:Proto-Oncogene Proteins c-fyn; D012333:RNA, Messenger / Q000032:analysis; D015398:Signal Transduction / Q000502:physiology; D015027:Zebrafish; D029961:Zebrafish Proteins; D018909:src Homology Domains / Q000235:genetics
D000906:Antibodies; D000936:Antigen-Antibody Complex; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D029961:Zebrafish Proteins; D051076:Proto-Oncogene Proteins c-fyn; C494964:fyna protein, zebrafish