AnnoDPO: Protein Functional Annotation Learning with Direct Preference Optimization
1.This study introduces AnnoDPO, a novel multimodal framework that improves protein functional annotation by integrating Direct Preference Optimization (DPO), a reinforcement learning variant, into protein language model training.
2.AnnoDPO addresses two major challenges in protein function prediction: the scarcity of annotated data and the highly imbalanced distribution of functional categories, using preference-aligned training objectives inspired by reinforcement learning from human feedback (RLHF).
3.The framework consists of three training stages: pretraining a protein sequence encoder (ESM-C), supervised finetuning combining annotation prediction and sequence-annotation contrastive learning, and finally DPO to optimize preferences directly without explicit reward modeling.
4.DPO enhances model attention patterns, enabling better capture of hierarchical relationships within Gene Ontology (GO) terms, which improves discrimination among biological processes, molecular functions, and cellular components.
5.Experimentally, AnnoDPO consistently outperforms baseline models in multiple Gene Ontology categories, showing significant gains in F1-Max scores across biological process, cellular component, and molecular function annotations.
6.The model demonstrates improved robustness across label frequency groups, particularly excelling at predicting rare (low-frequency) protein function annotations through its preference optimization approach.
7.Visualization of latent embeddings reveals that AnnoDPO achieves clearer functional category separability and preserves fine-grained ontological relationships, supporting biologically meaningful annotation predictions.
8.Ablation studies confirm that both contrastive learning and DPO contribute critically to performance gains, with DPO-powered models achieving state-of-the-art results without relying on complex reward modeling.
9.The authors release the code for AnnoDPO, promoting reproducibility and further development in protein functional annotation research.
💻Code:
github.com/AzusaXuan/AnnoDPO
📜Paper:
arxiv.org/abs/2506.07035v1
#ProteinFunction #Bioinformatics #MachineLearning #ProteinLanguageModels #ReinforcementLearning #DirectPreferenceOptimization #GeneOntology #ComputationalBiology