Direct Functional Interaction of the Kinesin-13 Family Member Kinesin-like Protein 2A (Kif2A) and Arf GAP with GTP-binding Protein-like, Ankyrin Repeats and PH Domains1 (AGAP1)

A de novo 2q37.2 deletion encompassing AGAP1 and SH3BP4 in a patient with autism and intellectual disability

Autism spectrum disorders are complex neurodevelopmental syndromes characterized by phenotypic and genetic heterogeneity. Further identification of causal genes may help in better understanding the underlying mechanisms of the disorder, thus improving the patients' management. To date, abnormal synaptogenesis is thought to be one of the major underlying causes of autism spectrum disorders. Here, using oligoarray-based comparative genomic hybridization, we identified a de novo deletion at 2q37.2 locus spanning 1 Mb and encompassing AGAP1 and SH3BP4, in a boy with autism and intellectual disability. Both genes have been described as being involved in endosomal trafficking, and AGAP1 in particular has been shown to be expressed in the developing brain and to play a role in dendritic spine formation and synapse function, making it a potential causative gene to our patient's phenotype.

Activating Wnt/β-catenin signaling pathway for disease therapy: Challenges and opportunities

Wnt/β-catenin signaling pathway is essential for embryo development and adult tissue homeostasis and regeneration, abnormal regulation of the pathway is tightly associated with many disease types, suggesting that Wnt/β-catenin signaling pathway is an attractive target for disease therapy. While the Wnt inhibitors have been extensively reviewed, small molecules activating Wnt/β-catenin signaling were rarely addressed. In this article, we firstly reviewed the diseases that were associated with disruption of Wnt/β-catenin signaling pathway, including hair loss, pigmentary disorders, wound healing, bone diseases, neurodegenerative diseases and chronic obstructive pulmonary diseases, etc. We also comprehensively summarized small molecules that activated Wnt/β-catenin signaling pathway in various models in vitro and in vivo. To evaluate the therapeutic potential of Wnt activation, we focused on the discovery strategies, phenotypic characterization, and target identification of the Wnt activators. Finally, we proposed the challenges and opportunities in development of Wnt activators for pharmacological agents in term of targeting safety and selectivity.

Arf GAPs and molecular motors

Arf GTPase-activating proteins (Arf GAPs) were first identified as regulators of the small GTP-binding proteins ADP-ribosylation factors (Arfs). The Arf GAPs are a large family of proteins in metazoans, outnumbering the Arfs that they regulate. The members of the Arf GAP family have complex domain structures and some have been implicated in particular cellular functions, such as cell migration, or with particular pathologies, such as tumor invasion and metastasis. The specific effects of Arfs sometimes depend on the Arf GAP involved in their regulation. These observations have led to speculation that the Arf GAPs themselves may affect cellular activities in capacities beyond the regulation of Arfs. Recently, 2 Arf GAPs, ASAP1 and AGAP1, have been found to bind directly to and influence the activity of myosins and kinesins, motor proteins associated with filamentous actin and microtubules, respectively. The Arf GAP-motor protein interaction is critical for cellular behaviors involving the actin cytoskeleton and microtubules, such as cell migration and other cell movements. Arfs, then, may function with molecular motors through Arf GAPs to regulate microtubule and actin remodeling.