Biology subjects

Akarlar, B. A.

Publications and source records attributed to Akarlar, B. A..

3 recordsLinked to original sources

bioRxiv2023

TW68, Cryptochromes stabilizer, regulates fasting blood glucose level in ob/ob and fat-induced diabetic mice

Cryptochromes (CRYs), transcriptional repressors of the circadian clock in mammals, inhibit cAMP production when glucagon activates G-protein coupled receptors. Therefore, molecules that modulate CRYs have the potential to regulate gluconeogenesis. In this study, we discovered a new molecule called TW68 that interacts with the primary pockets of mammalian CRY1/2, leading to reduced ubiquitination levels and increased stability. In cell-based circadian rhythm assays using U2OS:Bmal1-dLuc cells, TW68 extended the period length of the circadian rhythm. Additionally, TW68 decreased the transcriptional levels of two genes, Phosphoenolpyruvate carboxykinase 1 (PCK1) and Glucose-6-phosphatase (G6PC), which play crucial roles in glucose biosynthesis during glucagon-induced gluconeogenesis in HepG2 cells. Oral administration of TW68 in mice showed good tolerance, a good pharmacokinetic profile, and remarkable bioavailability. Finally, when administered to fasting ob/ob and fat-induced diabetic animals, TW68 reduced blood glucose levels by enhancing CRY stabilization and subsequently decreasing the transcriptional levels of Pck1 and G6pc. These findings collectively demonstrate the antidiabetic efficacy of TW68 in vivo, suggesting its therapeutic potential for controlling fasting glucose levels in the treatment of type 2 diabetes mellitus.

molecular biology↗

bioRxiv2020

REEP4 is recruited to the inner nuclear membrane by ELYS and promotes nuclear pore complex formation

Nuclear pore complexes (NPCs) are channels within the nuclear envelope that mediate nucleocytoplasmic transport. NPCs assemble either into the closed nuclear envelope during interphase or concomitantly with nuclear envelope reformation during anaphase. Both, interphase and post-mitotic NPC biogenesis require local deformation of membrane. Yet, the factors that control proper membrane remodeling for post-mitotic NPC assembly are unknown. Here, we report that the reticulon homology domain-protein REEP4 localizes not only to high-curvature membrane of the cytoplasmic endoplasmic reticulum (ER) but also to the inner nuclear membrane (INM). We show that REEP4 is recruited to the INM by the NPC biogenesis factor ELYS and promotes NPC assembly. REEP4 contributes mainly to anaphase NPC assembly, suggesting that REEP4 has an unexpected role in coordinating nuclear envelope reformation with post-mitotic NPC biogenesis.

cell biology↗

bioRxiv2020

Roles of developmentally regulated KIF2A alternative isoforms in cortical neuron migration and differentiation

KIF2A is a microtubule-depolymerizing kinesin motor protein with essential roles in neural progenitor division and axonal pruning during brain development. KIF2A is alternatively spliced in nervous tissue by specific RNA-binding proteins. However, how different KIF2A isoforms function during development of the cerebral cortex is not known. Here, we focus on three Kif2a isoforms expressed in mouse embryonic and postnatal cerebral cortex. We show that KIF2A is essential for dendritic pruning of primary cortical neurons in mice and that the functions of all three isoforms are sufficient for this process. Interestingly, only two of the isoforms can sustain radial migration of cortical neurons while a third isoform, lacking a key stretch of twenty amino acids, is ineffective. By proximity-labeling-based interactome mapping for individual KIF2A isoforms, we provide novel insight into how isoform specific interactions can confer changes to KIF2A protein function. Our interactome mapping identifies previously known KIF2A interactors, proteins localized to the mitotic spindle poles, and unexpectedly, also translation factors, ribonucleoproteins and proteins that are targeted to the mitochondria and ER, suggesting a novel transport function for KIF2A.

developmental biology↗