Mutation in P0, a dual function ribosomal protein/apurinic/apyrimidinic endonuclease, modifies gene expression and position effect variegation in Drosophila
Mv. Frolov et Ja. Birchler, Mutation in P0, a dual function ribosomal protein/apurinic/apyrimidinic endonuclease, modifies gene expression and position effect variegation in Drosophila, GENETICS, 150(4), 1998, pp. 1487-1495
In a search for modifiers of gene expression with the white eye color gene
as a target, a third chromosomal P-element insertion mutant l(3)01544 has b
een identified that exhibits a strong pigment increase in a white-apricot b
ackground. Molecular analysis shows that the P-element insertion is found i
n the first intron of the gene surrounding the insertion site. Sequencing b
oth the cDNA and genomic fragments revealed that the identified gene is ide
ntical to one encoding ribosomal protein P0/apurinic/apyrimidinic endonucle
ase. The P-element-induced mutation, l(3)01544, affects the steady-state le
vel of white transcripts and transcripts of some other genes. In addition,
l(3)01544 suppresses the variegated phenotypes of In(1)w(m4h) and In(1)y(3P
), suggesting a potential involvement of the PO protein in modifying positi
on effect variegation. The revertant generated by the precise excision of t
he P element has lost all mutant phenotypes. Recent work revealed that Dros
ophila ribosomal protein PO contains an apurinic/apyrimidinic endonuclease
activity. Our results suggest that this multifunctional protein is also inv
olved in regulation of gene expression in Drosophila.