NCBI Summary:
Fer protein is a member of the FPS/FES family of nontransmembrane receptor tyrosine kinases. It regulates cell-cell adhesion and mediates signaling from the cell surface to the cytoskeleton via growth factor receptors. [provided by RefSeq, Jul 2008]
General function
Enzyme, Transferase
Comment
Cellular localization
Cytoplasmic, Nuclear
Comment
Ovarian function
Oogenesis, Oocyte maturation
Comment
Fer tyrosine kinase is required for germinal vesicle breakdown and meiosis-I in mouse oocytes. McGinnis LK et al. The control of microtubule and actin-mediated events that direct the physical arrangement and separation of chromosomes during meiosis is critical since failure to maintain chromosome organization can lead to germ cell aneuploidy. Our previous studies demonstrated a role for FYN tyrosine kinase in chromosome and spindle organization and in cortical polarity of the mature mammalian oocyte. In addition to Fyn, mammalian oocytes express the protein tyrosine kinase Fer at high levels relative to other tissues. The objective of the present study was to determine the function of this kinase in the oocyte. Feline encephalitis virus (FES)-related kinase (FER) protein was uniformly distributed in the ooplasm of small oocytes, but became concentrated in the germinal vesicle (GV) during oocyte growth. After germinal vesicle breakdown (GVBD), FER associated with the metaphase-I (MI) and metaphase-II (MII) spindles. Suppression of Fer expression by siRNA knockdown in GV stage oocytes did not prevent activation of cyclin dependent kinase 1 activity or chromosome condensation during in vitro maturation, but did arrest oocytes prior to GVBD or during MI. The resultant phenotype displayed condensed chromosomes trapped in the GV, or condensed chromosomes poorly arranged in a metaphase plate but with an underdeveloped spindle microtubule structure or chromosomes compacted into a tight sphere. The results demonstrate that FER kinase plays a critical role in oocyte meiotic spindle microtubule dynamics and may have an additional function in GVBD. Mol. Reprod. Dev. 78:33-47, 2011.