PP1 localisation is regulated by dPNUTS and binding to PP1 is important for dPNUTS function.

A) Images of polytene chromosome squashes from salivary glands expressing either dPNUTSWT or dPNUTSW726A stained with PP1 (in green). Inset are enlarged views of the distal end of the X chromosome. Arrows indicate approximate lines along which quantitation of fluorescence (see B) was performed. B) Plots of line scans through the chromosomal region indicated in A, showing levels of PP1 staining in salivary glands expressing either dPNUTSWT or dPNUTSW726A. Bar graphs represent the average fluorescence in this region from 6 independent images/genotype. Genotypes are indicated by the colour key. C) Levels and distribution of Myc-dPNUTS on polytene chromosome squashes from salivary glands expressing either dPNUTSWT or dPNUTSW726A, as revealed by anti-Myc staining (green). D) Western blots showing levels of PP1 and Myc-dPNUTS, relative to Actin, in extracts from animals ectopically expressing dPNUTSWT or dPNUTSW726A under the control of da-GAL4 (da>dPNUTSWT and da>dPNUTSW726A, respectively) compared to w1118 control (−). E) Images of adult female eyes showing that the severely reduced eye phenotype of homozygous dPNUTS mutant eyes is fully rescued by ectopic expression of dPNUTSWT but not dPNUTSW726A. F) Homozygous dPNUTSKG572 mutant eyes show a weaker phenotype than either dPNUTS9B or dPNUTS13B, and this can be enhanced by loss of one copy of PP187B.