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Orb2 the Drosophila homolog of cytoplasmic polyadenylation element binding (CPEB) protein forms prion-like oligomers. These oligomers consist of Orb2A and Orb2B isoforms and their formation is dependent on the oligomerization of the Orb2A isoform. Drosophila with a mutation diminishing Orb2A's prion-like oligomerization forms long-term memory but fails to maintain it over time. Since this prion-like oligomerization of Orb2A plays a crucial role in the maintenance of memory, here, we aim to find what regulates this oligomerization. In an immunoprecipitation-based screen, we identify interactors of Orb2A in the Hsp40 and Hsp70 families of proteins. Among these, we find an Hsp40 family protein Mrj as a regulator of the conversion of Orb2A to its prion-like form. Mrj interacts with Hsp70 proteins and acts as a chaperone by interfering with the aggregation of pathogenic Huntingtin. Unlike its mammalian homolog, we find Drosophila Mrj is neither an essential gene nor causes any gross neurodevelopmental defect. We observe a loss of Mrj results in a reduction in Orb2 oligomers. Further, Mrj knockout exhibits a deficit in long-term memory and our observations suggest Mrj is needed in mushroom body neurons for the regulation of long-term memory. Our work implicates a chaperone Mrj in mechanisms of memory regulation through controlling the oligomerization of Orb2A and its association with the translating ribosomes. Orb2, the Drosophila homolog of CPEB, forms prion-like oligomers that play a crucial role in the maintenance of long-term memory. This study identifies the Hsp40 family chaperone Mrj as a regulator of Orb2 oligomerization and its association with translating ribosomes. [ABSTRACT FROM AUTHOR]

The article focuses on the Eleventh RNA Group Meeting in India, serving as a premier forum for discussing recent advancements in RNA biology. Topics covered include RNA translation mechanisms, RNA processing dynamics, and the role of RNA-binding proteins in disease pathology, highlighting diverse aspects from molecular processes to clinical implications.

As the interface between the body and the environment, the skin functions as the physical barrier against external pathogens and toxic agents. In addition, the skin is an immunologically active organ with a plethora of resident adaptive and innate immune cells, as well as effector molecules that provide another layer of protection in the form of an immune barrier. A major subpopulation of these immune cells are the Foxp3 expressing CD4 T cells or regulatory T cells (Tregs). The canonical function of T-regs is to keep other immune cells in check during homeostasis or to dissipate a robust inflammatory response following pathogen clearance or wound healing. Interestingly, recent data has uncovered unconventional roles that vary between different tissues and we will highlight the emerging non-lymphoid functions of cutaneous T-regs. In light of the novel functions of other immune cells that are routinely being discovered in the skin, their regulation by T-regs implies that T-regs have executive control over a broad swath of biological activities in both homeostasis and disease. The blossoming list of non-inflammatory functions, whether direct or indirect, suggests that the role of T-regs in a regenerative organ such as the skin will be a field ripe for discovery for decades to come. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cell.2010.01.008 Byline: Kausik Si (1)(2), Yun-Beom Choi (5)(6), Erica White-Grindley (1), Amitabha Majumdar (1), Eric R. Kandel (3)(4)(5) Keywords: MOLNEURO; CELLBIO; PROTEINS Abstract: Prions are proteins that can assume at least two distinct conformational states, one of which is dominant and self-perpetuating. Previously we found that a translation regulator CPEB from Aplysia, ApCPEB, that stabilizes activity-dependent changes in synaptic efficacy can display prion-like properties in yeast. Here we find that, when exogenously expressed in sensory neurons, ApCPEB can form an amyloidogenic self-sustaining multimer, consistent with it being a prion-like protein. In addition, we find that conversion of both the exogenous and the endogenous ApCPEB to the multimeric state is enhanced by the neurotransmitter serotonin and that an antibody that recognizes preferentially the multimeric ApCPEB blocks persistence of synaptic facilitation. These results are consistent with the idea that ApCPEB can act as a self-sustaining prion-like protein in the nervous system and thereby might allow the activity-dependent change in synaptic efficacy to persist for long periods of time. Author Affiliation: (1) Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA (2) Department of Molecular & Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA (3) Howard Hughes Medical Institute, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, 722 West 168.sup.th Street, New York, NY 10032, USA (4) Kavli Institute for Brain Science, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, 722 West 168.sup.th Street, New York, NY 10032, USA (5) Department of Neuroscience, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, 722 West 168.sup.th Street, New York, NY 10032, USA (6) Department of Neurology, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, 722 West 168.sup.th Street, New York, NY 10032, USA Article History: Received 3 October 2008; Revised 20 July 2009; Accepted 5 January 2010 Article Note: (miscellaneous) Published: February 4, 2010

The nucleocapsid protein N of chandipura virus is prone to aggregation and the P-protein is able to suppress this aggregation. The P-protein is thus an N-protein-specific chaperone that prevents the nucleation phase of N-protein aggregation.