Multifaceted roles of MAGOH Proteins.

MAGOH and MAGOHB are paralog proteins that can substitute each other in the exon junction complex (EJC). The EJC is formed of core components EIF4A3, RBM8A, and MAGOH/MAGOHB. As a part of the EJC, MAGOH proteins are required for mRNA splicing, export, translation and nonsense-mediated mRNA decay (NMD). MAGOH is also essential for embryonic development and normal cellular functioning. The haploinsufficiency of MAGOH results in disorders such as microcephaly and cancer. The present review discusses the discovery of MAGOH, its paralog MAGOHB, their roles in cellular function as part of the EJC, and other cellular roles that are not directly associated with mRNA processing. We also discuss how MAGOH haploinsufficiency in cancer cells can be exploited to develop a novel targeted cancer treatment.

Enhanced fluorescence blinking of AF647 fluorophores in Mowiol via violet and UV light induced recovery for superior localization microscopy.

Blinking of fluorophores is essential in the context of single molecule localization-based optical super-resolution microscopy methods. To make the fluorescence molecule undergo blinking specific complex chemical mounting buffer systems, combined with suitable oxygen scavengers, and reducing agents are required. For instance to realise blinking in widely used fluorescence tags, like Alexa Fluor 647 (AF647), they are to be mounted on anti-fading buffer such as Mowiol and reducing agent such as Beta (ß) - ME. However, the quality of the super-resolved images is decided by the total number of blinking events or in other words net duration for which the fluorescence blinking persists. In this paper we investigate how a violet and UV light induced fluorescence recovery mechanism can enhance the duration of fluorescence blinking. Our study uses AF647 dye conjugated with Phalloidin antibody in U87MG cell line mounted on Mowiol andß- ME. On the basis of the investigation we optimize the intensity, at the sample plane, of fluorescence excitation laser at 638 nm and fluorescence recovery beam at 405 nm or in the UV giving the maximum possible fluorescence blinking duration. We observe that the longer blinking duration, using the optimized illumination scheme, has brought down the resolution in the super-resolved image, as given by Fourier Ring Correlation method, from 168 nm to 112 nm, while the separation between two nearby resolvable filaments has been brought down to ≤ 60 nm.