Nuclear and cytoplasmic localization of different basic fibroblast growth factor species.
The subcellular distribution of basic fibroblastic growth factor (bFGF) was analyzed by subcellular fractionation and immunofluorescence to gain insight into potential mechanisms for its release from cells. Subcellular fractionation of either SK-Hep-1 cells or NIH 3T3 cells transfected with a bFGF cDNA revealed that the 18 kd form of bFGF was found primarily in the cytosolic fraction, whereas the 22 and 24 kd forms of bFGF were found preferentially in ribosomal and nuclear fractions. Analysis of bFGF distribution by immunofluorescence using an antibody that recognized all forms of bFGF indicated both cytoplasmic and nuclear localization but failed to reveal any growth factor in structures representing secretory vesicles. Therefore, bFGF has a distribution inconsistent with that of a secretory protein.
Department of Cell Biology, New York University Medical Center, New York.
M
M
Renko
N
N
Quarto
T
T
Morimoto
D B
DB
Rifkin
D000818:Animals; D015153:Blotting, Western; D002451:Cell Compartmentation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000145:classification / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D051379:Mice; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D013347:Subcellular Fractions / Q000378:metabolism; D014357:Trypsin / Q000494:pharmacology
D009687:Nuclear Proteins; D012333:RNA, Messenger; D005346:Fibroblast Growth Factors; D014357:Trypsin