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Feinauer, C.

Publications and source records attributed to Feinauer, C..

8 recordsLinked to original sources

Foundation Models Improve Perturbation Response Prediction

Predicting cellular responses to genetic or chemical perturbations has been a long-standing goal in biology. Recent applications of foundation models to this task have yielded contradictory results regarding their superiority over simple baselines. We conducted an extensive analysis of over 600 different models across various prediction tasks and evaluation metrics, demonstrating that while some foundation models fail to outperform simple baselines, others significantly improve predictions for both genetic and chemical perturbations. Furthermore, we developed and evaluated methods for integrating multiple foundation models for perturbation prediction. Our results show that with sufficient data, these models approach fundamental performance limits, confirming that foundation models can improve cellular response simulations. Code and Data: https://github.com/genbio-ai/foundation-models-perturbation

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Uncertainty-Aware Discrete Diffusion Improves Protein Design

Protein inverse folding involves generating amino acid sequences that adopt a specified 3D structure--a key challenge in structural biology and molecular engineering. While discrete diffusion models have demonstrated strong performance, existing methods often apply uniform denoising across residues, overlooking position-specific uncertainty. We propose an uncertainty-aware discrete denoising diffusion model that employs a prior-posterior signaling mechanism to dynamically guide the denoising process. Our approach further integrates learned priors from a pretrained protein large language model and a structure encoder within a modular framework, jointly optimized through multi-objective training. Across multiple benchmarks, our method achieves substantial improvements over state-ofthe-art baselines, offering a principled framework for structure-conditioned sequence generation in proteins and beyond.

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TULIP - a Transformer based Unsupervised Language model for Interacting Peptides and T-cell receptors that generalizes to unseen epitopes

The accurate prediction of binding between T-cell receptors (TCR) and their cognate epitopes is key to understanding the adaptive immune response and developing immunotherapies. Current methods face two significant limitations: the shortage of comprehensive high-quality data and the bias introduced by the selection of the negative training data commonly used in the supervised learning approaches. We propose a novel method, TULIP, that addresses both limitations by leveraging incomplete data and unsupervised learning and using the transformer architecture of language models. Our model is flexible and integrates all possible data sources, regardless of their quality or completeness. We demonstrate the existence of a bias introduced by the sampling procedure used in previous supervised approaches, emphasizing the need for an unsupervised approach. TULIP recognizes the specific TCRs binding an epitope, performing well on unseen epitopes. Our model outperforms state-of-the-art models and offers a promising direction for the development of more accurate TCR epitope recognition models.

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Mean Dimension of Generative Models for Protein Sequences

AO_SCPLOWBSTRACTC_SCPLOWGenerative models for protein sequences are important for protein design, mutational effect prediction and structure prediction. In all of these tasks, the introduction of models which include interactions between pairs of positions has had a major impact over the last decade. More recently, many methods going beyond pairwise models have been developed, for example by using neural networks that are in principle able to capture interactions between more than two positions from multiple sequence alignments. However, not much is known about the inter-dependency patterns between positions in these models, and how important higher-order interactions involving more than two positions are for their performance. In this work, we introduce the notion of mean dimension for generative models for protein sequences, which measures the average number of positions involved in interactions when weighted by their contribution to the total variance in log probability of the model. We estimate the mean dimension for different model classes trained on different protein families, relate it to the performance of the models on mutational effect prediction tasks and also trace its evolution during training. The mean dimension is related to the performance of models in biological prediction tasks and can highlight differences between model classes even if their performance in the prediction task is similar. The overall low mean dimension indicates that well-performing models are not necessarily of high complexity and encourages further work in interpreting their performance in biological terms.

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Context-Aware Generative Models for Multi-Domain Proteins using Transformers

MotivationBeing able to artificially design novel proteins of desired function is pivotal in many biological and biomedical applications. Generative statistical modeling has recently emerged as a new paradigm for designing amino acid sequences, including in particular models and embedding methods borrowed from Natural Language Processing (NLP). However, most approaches target single proteins or protein domains, and do not take into account any functional specificity or interaction with the context. To extend beyond current computational strategies, we develop a method for generating protein domain sequences intended to interact with another protein domain. Using data from natural multi-domain proteins, we cast the problem as a translation problem from a given interactor domain to the new domain to be generated, i.e. we generate artificial partner sequences conditional on an input sequence. ResultsEvaluating our models quality using diverse metrics, in part related to distinct biological questions, we show that our method outperforms state-of-the-art shallow auto-regressive strategies. We also explore the possibility of fine-tuning pre-trained large language models for the same task and of using Alphafold 2 for assessing the quality of sampled sequences.

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Interpretable Pairwise Distillations for Generative Protein Sequence Models

AO_SCPLOWBSTRACTC_SCPLOWMany different types of generative models for protein sequences have been proposed in literature. Their uses include the prediction of mutational effects, protein design and the prediction of structural properties. Neural network (NN) architectures have shown great performances, commonly attributed to the capacity to extract non-trivial higher-order interactions from the data. In this work, we analyze three different NN models and assess how close they are to simple pairwise distributions, which have been used in the past for similar problems. We present an approach for extracting pairwise models from more complex ones using an energy-based modeling framework. We show that for the tested models the extracted pairwise models can replicate the energies of the original models and are also close in performance in tasks like mutational effect prediction.

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Natural representation of composite data with replicated autoencoders

Generative processes in biology and other fields often produce data that can be regarded as resulting from a composition of basic features. Here we present an unsupervised method based on autoencoders for inferring these basic features of data. The main novelty in our approach is that the training is based on the optimization of the local entropy rather than the standard loss, resulting in a more robust inference, and enhancing the performance on this type of data considerably. Algorithmically, this is realized by training an interacting system of replicated autoencoders. We apply this method to synthetic and protein sequence data, and show that it is able to infer a hidden representation that correlates well with the underlying generative process, without requiring any prior knowledge.\n\nAUTHOR SUMMARYExtracting compositional features from noisy data and identifying the corresponding generative models is a fundamental challenge across sciences. The composition of elementary features can have highly non-linear effects which makes them very hard to identify from experimental data.\n\nIn biology, for instance, one challenge is to identify the key steps or components of molecular and cellular processes. Representative examples are the modeling of protein sequences as the composition of patterns influenced by phylogeny or the identification of gene clusters in which the presence of specific genes depends on the evolutionary history of the cell.\n\nHere we present an unsupervised machine learning technique for the analysis of compositional data which is based on entropic neural autoencoders. Our approach aims at finding deep autoencoders that are highly invariant with respect to perturbations in the inputs and in the parameters. The procedure is efficient to implement and we have validated it both on synthetic and protein sequence data, where it can be shown that the latent variables of the autoencoders are non trivially correlated with the true underlying generative processes. Our results suggests that the local entropy approach represents a general valuable tool for the extraction of compositional features in hard unsupervised learning problems.

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Context-Aware Prediction of Pathogenicity of Missense Mutations Involved in Human Disease

Amino-acid substitutions are implicated in a wide range of human diseases, many of which are lethal. Distinguishing such mutations from polymorphisms without significant effect on human health is a necessary step in understanding the etiology of such diseases. Computational methods can be used to select interesting mutations within a larger set, to corroborate experimental findings and to elucidate the cause of the deleterious effect. In this work, we show that taking into account the sequence context in which the mutation appears allows to improve the predictive and explanatory power of such methods. We present an unsupervised approach based on the direct-coupling analysis of homologous proteins. We show its capability to quantify mutations where methods without context dependence fail. We highlight cases where the context dependence is interpretable as functional or structural constraints and show that our simple and unsupervised method has an accuracy similar to state-of-the-art methods, including supervised ones.

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