BDNF-induced phosphorylation of TRKB is reduced in <i>BBS4</i>-deficient cells.

<p>(A) Western blot detection in hTERT-RPE1 cells of phosphorylated TRKB (pTRKB) and unphosphorylated TRKB, as well as Actin as loading control, in the presence or absence of BDNF and the presence or absence of short hairpin targeting expression of <i>BBS4</i> (sh<i>BBS4</i>). (B) Average activation of TRKB in hTERT-RPE1 cells quantified as the amount of pTRKB relative to the amount of TRKB for indicated treatments measured by ImageJ densitometry analysis. Error bars depict standard deviation across a minimum of 3 experiments. *significant change (p<0.01, t-test) from control; **significant change (p<0.01, t-test) from BDNF-treated control cells. (C) Western blot detection in hTERT-RPE1 cells of pTRKB and TRKB, as well as Actin, in the presence or absence of BDNF and the presence or absence of a short hairpin targeting the 3′UTR (sh<i>BBS4</i>) or a vector expressing <i>BBS4</i> (BBS4). (D) Quantification of the average activation of TRKB in hTERT-RPE1 cells quantified as the amount of pTRKB relative to the amount of TRKB for indicated treatments. *significant change (p<0.01, t-test) from control; **significant change (p<0.05, t-test) from BDNF-treated control. (E) Western blot detection SH-SY5Y cells pTRKB and TRKB in the presence of absence of BDNF and the presence or absence of sh<i>BBS4</i>. (F) Average activation of TRKB in SH-SY5 cells quantified as the amount of pTRKB relative to the amount of TRKB for indicated treatments. Error bars depict standard deviation across a minimum of 3 experiments. *significant change (p<0.01, t-test) from control; **significant change (p<0.01, t-test) from BDNF-treated control cells.