![Figure 10. SerCDK phosphorylation promotes dynamic instability of MT-associated Drp1. (A–C) Cdk5 inhibition by roscovitine (10 µM) attenuates fluorescence recovery of wild-type Drp1-101, but has no effect on the SerCDKAla mutant. (A) shows time frames of FRAP in representative HeLa cells expressing wild-type and SerPKAAla GFP-Drp1-101, recovery curves (B), and mobile fractions (C) derived from biexponential fits of the recovery data (means ± SEM [up]/SD [down] of 6–8 cells). (D and E) Time-lapse video microscopy of HeLa cells expressing the indicated GFP-tagged proteins shows that Drp1-101 polymers shrink and expand in a Cdk5- and SerCDK-dependent manner (see also Video 3). (D, left) Time frames of representative cells, with dotted outlines marking Drp1-x01 tracks about to undergo shrinkage or expansion. (D, right) Mean z-projections of inter-frame difference images from which motility indices (0–1) are calculated (E; means ± SEM [up]/SD [down] of 31–41 whole cells). Ø, P = 0.001; ⊗, P < 0.0001 compared with Drp1-101 wild-type basal. (F and G) Models of regulated MT association of Drp1 (see text).](https://cdn.rupress.org/rup/content_public/journal/jcb/201/7/10.1083_jcb.201210045/5/jcb_201210045_fig10.jpeg?Expires=1767713536&Signature=pMrEjCIEtxb0dbPKie~~DkahAbo6YkhzroJAJzONbvmaxxbOVn9UL~FCbcFJ5gh1I8DfyNq0iSgFLepq16S--tH8hA-mnd1mQ1r~3d8sWulaoKMGtVfZXHHHhOiulMhSjGCKJ2JAJDZlfFDXtNB2gVrIP-njCLBkmHQt1Iersa22RG3v1R5rNxtl9HcA5f58uU1T1Q1tINYiVtj4LwQr-uNAk~9-eiofmVsf1tLXbiPjjevryLnNfVLYtzjmkwuspK-utdnkHMsvBemwfKBj0pf0JBOf3L3SOET73tg~eoFg8KaLKMyk6LTV-5mb-FhXl8SD39vX1eMGvhhRKLvjOQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
SerCDK phosphorylation promotes dynamic instability of MT-associated Drp1. (A–C) Cdk5 inhibition by roscovitine (10 µM) attenuates fluorescence recovery of wild-type Drp1-101, but has no effect on the SerCDKAla mutant. (A) shows time frames of FRAP in representative HeLa cells expressing wild-type and SerPKAAla GFP-Drp1-101, recovery curves (B), and mobile fractions (C) derived from biexponential fits of the recovery data (means ± SEM [up]/SD [down] of 6–8 cells). (D and E) Time-lapse video microscopy of HeLa cells expressing the indicated GFP-tagged proteins shows that Drp1-101 polymers shrink and expand in a Cdk5- and SerCDK-dependent manner (see also Video 3). (D, left) Time frames of representative cells, with dotted outlines marking Drp1-x01 tracks about to undergo shrinkage or expansion. (D, right) Mean z-projections of inter-frame difference images from which motility indices (0–1) are calculated (E; means ± SEM [up]/SD [down] of 31–41 whole cells). Ø, P = 0.001; ⊗, P < 0.0001 compared with Drp1-101 wild-type basal. (F and G) Models of regulated MT association of Drp1 (see text).
