5a6c
From Proteopedia
Concomitant binding of Afadin to LGN and F-actin directs planar spindle orientation
Structural highlights
Disease[GPSM2_HUMAN] Autosomal recessive nonsyndromic sensorineural deafness type DFNB;Chudley-McCullough syndrome. Chudley-McCullough syndrome (CMCS) [MIM:604213]: An autosomal recessive neurologic disorder characterized by early-onset sensorineural deafness and specific brain anomalies on MRI, including hypoplasia of the corpus callosum, enlarged cysterna magna with mild focal cerebellar dysplasia, and nodular heterotopia. Some patients have hydrocephalus. Psychomotor development is normal. Note=The disease is caused by mutations affecting the gene represented in this entry.[1] [2] Function[GPSM2_HUMAN] Plays an important role in spindle pole orientation. Interacts and contributes to the functional activity of G(i) alpha proteins. Acts to stabilize the apical complex during neuroblast divisions.[3] Publication Abstract from PubMedPolarized epithelia form by oriented cell divisions in which the mitotic spindle aligns parallel to the epithelial plane. To orient the mitotic spindle, cortical cues trigger the recruitment of NuMA-dynein-based motors, which pull on astral microtubules via the protein LGN. We demonstrate that the junctional protein Afadin is required for spindle orientation and correct epithelial morphogenesis of Caco-2 cysts. Molecularly, Afadin binds directly and concomitantly to F-actin and to LGN. We determined the crystallographic structure of human Afadin in complex with LGN and show that it resembles the LGN-NuMA complex. In mitosis, Afadin is necessary for cortical accumulation of LGN and NuMA above the spindle poles, in an F-actin-dependent manner. Collectively, our results depict Afadin as a molecular hub governing the enrichment of LGN and NuMA at the cortex. To our knowledge, Afadin is the first-described mechanical anchor between dynein and cortical F-actin. Concomitant binding of Afadin to LGN and F-actin directs planar spindle orientation.,Carminati M, Gallini S, Pirovano L, Alfieri A, Bisi S, Mapelli M Nat Struct Mol Biol. 2016 Jan 11. doi: 10.1038/nsmb.3152. PMID:26751642[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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