CK2-dependent C-terminal phosphorylation at T300 directs the nuclear transport of TSPY protein.
TSPY (testis-specific protein, Y-encoded) is a member of the greater SET/NAP family of molecules with various functions, e.g., in chromatin remodeling, regulation of gene expression, and has been implicated to play a role in the malignant development of gonadoblastoma, testicular and prostate cancer. Here we demonstrate that the C-terminus has a functional role for the nucleo-cytoplasmatic shuttling of the TSPY protein. Using various combinations of in vitro mutagenesis and enhanced green fluorescent protein reporter gene-expression experiments we were able to show that while the deletion of C-terminus leads to a decreased stability and enhanced degradation of the protein, the selective mutation of a C-terminal CK2 phosphorylation site (T300) prevents the TSPY protein from entering the nucleus. We conclude that phosphorylation of the (T300) residue is a necessary and functional prerequisite for TSPY's transport into the nucleus reminding of comparable data from a related Drosophila molecule, NAP1.
Krick
Roswitha
R
Institute of Human Genetics, Johann Wolfgang Goethe University Hospital, Frankfurt am Main, Germany.
Aschrafi
Amaz
A
Hasgün
Dilek
D
Arnemann
Joachim
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D047390:Casein Kinase II / Q000378:metabolism / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism* / Q000502:physiology; D002460:Cell Line; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D004330:Drosophila; D017353:Gene Deletion; D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation; D020125:Mutation, Missense; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D013997:Time Factors
D018797:Cell Cycle Proteins; D002843:Chromatin; D017931:DNA Primers; D011993:Recombinant Fusion Proteins; C497749:TSPY1 protein, human; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D047390:Casein Kinase II