Cell bio paper

What two roles had previously been identified for XMAP215?

XMAP215 promotes axon outgrowth by regulating microtubule polymerization and regulates the direction of growth cone trajectories.

What potential role for XMAP215 was being tested by the authors in this study?

The authors were testing the possibility that XMAP215 also regulates microtubule—F-actin interactions.

How does knockdown of XMAP215 affect growth cone area and filopodia length?

Knockdown of XMAP215 increases growth cone area and filopodia length.

How does knockdown of XMAP215 affect the number and duration of growth cone pauses?

Knockdown increases the number of pauses and the duration of pauses.

What effect does knockdown of XMAP215 have on axon length?

Knockdown decreases axon length.

What change occurs in the percentage of growth cones on ephrin stripes after XMAP215 knockdown?

Knockdown results in an increased percentage of growth cones on ephrin stripes.

What type of microtubule morphology is observed at a higher frequency upon XMAP215 knockdown?

Knockdown of XMAP215 results in an increase in microtubules that exhibit a looped morphology.

Are microtubules more or less dynamic in XMAP215 knockdown compared to controls?

Microtubules are more dynamic than controls in XMAP215 knockdown.

How does the percentage of exploring microtubules in filopodia compare in knockdown samples relative to control?

There is a reduced percentage of exploring microtubules in filopodia in knockdown samples compared to controls.

What effect does XMAP215 knockdown have on the alignment of F-actin and microtubules?

XMAP215 knockdown results in a significant decrease in the percentage of microtubules aligned to F-actin.

What effect does overexpression (OE) of XMAP215 have on alignment of F-actin and microtubules?

Overexpression of XMAP215 increases the percentage of aligned microtubules and F-actin.

Which region of XMAP215 is needed for the newly discovered functions based on data in Figure 6?

The TOG1-5 region is most important for the newly discovered functions of XMAP215.

What assay was used to test the ability of XMAP215 to bind directly to F-actin in Figure 7?

Co-sedimentation assays were used to test if XMAP215 binds directly to F-actin.

What did the results of the co-sedimentation assays show?

Experiments demonstrated that XMAP215 does interact with F-actin.

What is one question that still remains about how XMAP215 functions to regulate the cytoskeleton?

Can XMAP215 bind microtubules and F-actin at the same time?