The SQIP motif of CKIδ is required for centrosome polarization. (A) A schematic view of various GFP-fused CKIδ constructs is shown on top. Examples for conjugates formed between SEE-pulsed Raji cells and CKIδ-depleted Jurkat cells (shdelta) expressing the indicated GFP fusion product (green in merge). Asterisks mark cells with GFP signal. Centrosomes are stained with anti-CDK5RAP2 antibodies (red in merge). Raji cells are blue in merge. Bars, 10 µm. (B) A graph showing quantification of centrosome polarization to the IS in cells expressing the different GFP constructs (n = 4 experiments; at least 50 GFP-positive cells were scored per experiment). Error bars represent SD.