| 1. |
|
|
| 2. |
- Li, S. J., et al.
(författare)
-
The 1p36 Tumor Suppressor KIF 1B beta Is Required for Calcineurin Activation, Controlling Mitochondrial Fission and Apoptosis
- 2016
-
Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807 .- 1878-1551. ; 36:2, s. 164-178
-
Tidskriftsartikel (refereegranskat)abstract
- KIF1B beta is a candidate 1p36 tumor suppressor that regulates apoptosis in the developing sympathetic nervous system. We found that KIF1B beta activates the Ca2+-dependent phosphatase calcineurin (CN) by stabilizing the CN-calmodulin complex, relieving enzymatic autoinhibition and enabling CN substrate recognition. CN is the key mediator of cellular responses to Ca2+ signals and its deregulation is implicated in cancer, cardiac, neurodegenerative, and immune disease. We show that KIF1B beta affects mitochondria! dynamics through CN-dependent dephosphorylation of Dynamin-related protein 1 (DRP1), causing mitochondria! fission and apoptosis. Furthermore, KIF1B beta actuates recognition of all known CN substrates, implying a general mechanism for KIF1B beta in Ca2+ signaling and how Ca2+-dependent signaling is executed by CN. Pathogenic KIF1B beta mutations previously identified in neuroblastomas and pheochromocytomas all fail to activate CN or stimulate DRP1 dephosphorylation. Importantly, KIF1B beta and DRP1 are silenced in 1p36 hemizygous-deleted neuroblastomas, indicating that deregulation of calcineurin and mitochondria! dynamics contributes to high-risk and poor-prognosis neuroblastoma.
|
|
| 3. |
- Chen, Z. X., et al.
(författare)
-
RNA helicase a is a downstream mediator of KIF1Bβ tumor-suppressor function in neuroblastoma
- 2014
-
Ingår i: Cancer Discovery. - 2159-8274 .- 2159-8290. ; 4:4, s. 434-451
-
Tidskriftsartikel (refereegranskat)abstract
- Inherited KIF1B loss-of-function mutations in neuroblastomas and pheochromocytomas implicate the kinesin KIF1B as a 1p36.2 tumor suppressor. However, the mechanism of tumor suppression is unknown. We found that KIF1B isoform β (KIF1Bβ) interacts with RNA helicase A (DHX9), causing nuclear accumulation of DHX9, followed by subsequent induction of the proapoptotic XIAP-associated factor 1 (XAF1) and, consequently, apoptosis. Pheochromocytoma and neuroblastoma arise from neural crest progenitors that compete for growth factors such as nerve growth factor (NGF) during development. KIF1Bβ is required for developmental apoptosis induced by competition for NGF. We show that DHX9 is induced by and required for apoptosis stimulated by NGF deprivation. Moreover, neuroblastomas with chromosomal deletion of 1p36 exhibit loss of KIF1Bβ expression and impaired DHX9 nuclear localization, implicating the loss of DHX9 nuclear activity in neuroblastoma pathogenesis. SIGNIFICANCE: KIF1Bβ has neuroblastoma tumor-suppressor properties and promotes and requires nuclear-localized DHX9 for its apoptotic function by activating XAF1 expression. Loss of KIF1Bβ alters subcellular localization of DHX9 and diminishes NGF dependence of sympathetic neurons, leading to reduced culling of neural progenitors, and, therefore, might predispose to tumor formation.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
