TY - JOUR
AB - The quality control system for messenger RNA (mRNA) is fundamental for cellular activities in eukaryotes. To elucidate the molecular mechanism of 3'-Phosphoinositide-Dependent Protein Kinase1 (PDK1), a master regulator that is essential throughout eukaryotic growth and development, we employed a forward genetic approach to screen for suppressors of the loss-of-function T-DNA insertion double mutant pdk1.1 pdk1.2 in Arabidopsis thaliana. Notably, the severe growth attenuation of pdk1.1 pdk1.2 was rescued by sop21 (suppressor of pdk1.1 pdk1.2), which harbours a loss-of-function mutation in PELOTA1 (PEL1). PEL1 is a homologue of mammalian PELOTA and yeast (Saccharomyces cerevisiae) DOM34p, which each form a heterodimeric complex with the GTPase HBS1 (HSP70 SUBFAMILY B SUPPRESSOR1, also called SUPERKILLER PROTEIN7, SKI7), a protein that is responsible for ribosomal rescue and thereby assures the quality and fidelity of mRNA molecules during translation. Genetic analysis further revealed that a dysfunctional PEL1-HBS1 complex failed to degrade the T-DNA-disrupted PDK1 transcripts, which were truncated but functional, and thus rescued the growth and developmental defects of pdk1.1 pdk1.2. Our studies demonstrated the functionality of a homologous PELOTA-HBS1 complex and identified its essential regulatory role in plants, providing insights into the mechanism of mRNA quality control.
AU - Kong, W
AU - Tan, Shutang
AU - Zhao, Q
AU - Lin, DL
AU - Xu, ZH
AU - Friml, Jiří
AU - Xue, HW
ID - 9368
JF - Plant Physiology
SN - 0032-0889
TI - mRNA surveillance complex PELOTA-HBS1 eegulates phosphoinositide-sependent protein kinase1 and plant growth
ER -
TY - JOUR
AB - A central goal in systems neuroscience is to understand the functions performed by neural circuits. Previous top-down models addressed this question by comparing the behaviour of an ideal model circuit, optimised to perform a given function, with neural recordings. However, this requires guessing in advance what function is being performed, which may not be possible for many neural systems. To address this, we propose an inverse reinforcement learning (RL) framework for inferring the function performed by a neural network from data. We assume that the responses of each neuron in a network are optimised so as to drive the network towards ‘rewarded’ states, that are desirable for performing a given function. We then show how one can use inverse RL to infer the reward function optimised by the network from observing its responses. This inferred reward function can be used to predict how the neural network should adapt its dynamics to perform the same function when the external environment or network structure changes. This could lead to theoretical predictions about how neural network dynamics adapt to deal with cell death and/or varying sensory stimulus statistics.
AU - Chalk, Matthew J
AU - Tkačik, Gašper
AU - Marre, Olivier
ID - 9362
IS - 4 April
JF - PLoS ONE
TI - Inferring the function performed by a recurrent neural network
VL - 16
ER -
TY - JOUR
AB - We prove that the factorization homologies of a scheme with coefficients in truncated polynomial algebras compute the cohomologies of its generalized configuration spaces. Using Koszul duality between commutative algebras and Lie algebras, we obtain new expressions for the cohomologies of the latter. As a consequence, we obtain a uniform and conceptual approach for treating homological stability, homological densities, and arithmetic densities of generalized configuration spaces. Our results categorify, generalize, and in fact provide a conceptual understanding of the coincidences appearing in the work of Farb--Wolfson--Wood. Our computation of the stable homological densities also yields rational homotopy types, answering a question posed by Vakil--Wood. Our approach hinges on the study of homological stability of cohomological Chevalley complexes, which is of independent interest.
AU - Ho, Quoc P
ID - 9359
IS - 2
JF - Geometry & Topology
KW - Generalized configuration spaces
KW - homological stability
KW - homological densities
KW - chiral algebras
KW - chiral homology
KW - factorization algebras
KW - Koszul duality
KW - Ran space
SN - 1364-0380
TI - Homological stability and densities of generalized configuration spaces
VL - 25
ER -
TY - JOUR
AB - If there are no constraints on the process of speciation, then the number of species might be expected to match the number of available niches and this number might be indefinitely large. One possible constraint is the opportunity for allopatric divergence. In 1981, Felsenstein used a simple and elegant model to ask if there might also be genetic constraints. He showed that progress towards speciation could be described by the build‐up of linkage disequilibrium among divergently selected loci and between these loci and those contributing to other forms of reproductive isolation. Therefore, speciation is opposed by recombination, because it tends to break down linkage disequilibria. Felsenstein then introduced a crucial distinction between “two‐allele” models, which are subject to this effect, and “one‐allele” models, which are free from the recombination constraint. These fundamentally important insights have been the foundation for both empirical and theoretical studies of speciation ever since.
AU - Butlin, Roger K.
AU - Servedio, Maria R.
AU - Smadja, Carole M.
AU - Bank, Claudia
AU - Barton, Nicholas H
AU - Flaxman, Samuel M.
AU - Giraud, Tatiana
AU - Hopkins, Robin
AU - Larson, Erica L.
AU - Maan, Martine E.
AU - Meier, Joana
AU - Merrill, Richard
AU - Noor, Mohamed A. F.
AU - Ortiz‐Barrientos, Daniel
AU - Qvarnström, Anna
ID - 9374
JF - Evolution
KW - Genetics
KW - Ecology
KW - Evolution
KW - Behavior and Systematics
KW - General Agricultural and Biological Sciences
SN - 0014-3820
TI - Homage to Felsenstein 1981, or why are there so few/many species?
ER -
TY - JOUR
AB - Let t : Fp → C be a complex valued function on Fp. A classical problem in analytic number theory is bounding the maximum
M(t) := max 0≤H 0 there exists a large subset of a ∈ F×p such that for kl a,1,p : x → e((ax+x) / p) we have M(kla,1,p) ≥ (1−ε/√2π + o(1)) log log p, as p→∞. Finally, we prove a result on the growth of the moments of {M (kla,1,p)}a∈F×p. 2020 Mathematics Subject Classification: 11L03, 11T23 (Primary); 14F20, 60F10 (Secondary).
AU - Bonolis, Dante
ID - 9364
JF - Mathematical Proceedings of the Cambridge Philosophical Society
SN - 03050041
TI - On the size of the maximum of incomplete Kloosterman sums
ER -