bioRxiv Science⌕ Search

Biology subjects

Huan, C.

Publications and source records attributed to Huan, C..

3 recordsLinked to original sources

FAPM: Functional Annotation of Proteins using Multi-Modal Models Beyond Structural Modeling

Assigning accurate property labels to proteins, like functional terms and catalytic activity, is challenging, especially for proteins without homologs and "tail labels" with few known examples. Unlike previous methods that mainly focused on protein sequence features, we use a pretrained large natural language model to understand the semantic meaning of protein labels. Specifically, we introduce FAPM, a contrastive multi-modal model that links natural language with protein sequence language. This model combines a pretrained protein sequence model with a pretrained large language model to generate labels, such as Gene Ontology (GO) functional terms and catalytic activity predictions, in natural language. Our results show that FAPM excels in understanding protein properties, outperforming models based solely on protein sequences or structures. It achieves state-of-the-art performance on public benchmarks and in-house experimentally annotated phage proteins, which often have few known homologs. Additionally, FAPMs flexibility allows it to incorporate extra text prompts, like taxonomy information, enhancing both its predictive performance and explainability. This novel approach offers a promising alternative to current methods that rely on multiple sequence alignment for protein annotation. The online demo is at: https://huggingface.co/spaces/wenkai/FAPM_demo.

bioinformatics↗

Physiology and structure of pathogenic Escherichia coli pOmpT reveal two substrate-binding sites

The pathogenicity of bacteria can be achieved by cleaving antimicrobial peptides (AMPs) through the outer membrane protease family (Omptins) to evade or resist the hosts innate immune response. The OmpT-like proteins in Escherichia coli are members of Omptins, which have highly conserved proteolytic activity. Here, sequence alignment and physiological studies have determined that pOmpT is a virulence factor with atypical proteolytic activity. Comparing pOmpT with cOmpT in terms of structure, proteolytic activity and target substrates, it is found that Asp267 and Ser276 of cOmpT are substrate-binding sites and help its catalytic center to cleave substrates (protamine,synthetic peptide or RNase 7). However, special structural features and the nature of residues Ser267 and Thr276 of pOmpT caused the inability of cleavage protamine, but allows it to specifically cleave the human AMP RNase 7. It is suggested that two sites are related with the substrate specificity. In short, we found that pOmpT presents a new structural basis for the specific recognition of substrates, and providing new clues for the development of antimicrobial drugs.

microbiology↗

Myt Transcription Factors prevent stress-response gene over-activation to enable postnatal pancreatic β cell proliferation and function

Although stress response maintains cell function and survival under adverse conditions, over-activation of late-stage stress-gene effectors causes dysfunction and death. Here we show that the Myelin Transcription Factors (Myt 1, 2, and 3 TFs) prevent this over-activation. Co-inactivating Myt TFs in mouse pancreatic progenitors compromised postnatal {beta}-cell function, proliferation, and survival, preceded by upregulation of late-stage stress-response genes Activating Transcription Factors (e.g., Atf4) and Heat Shock Proteins (Hsps). Myt1 binds the putative enhancers of Atf4 and Hsps, whose over-expression in mouse {beta} cells largely recapitulated the Myt mutant phenotypes. Moreover, Myt(MYT)-TF levels were upregulated in functional mouse and human {beta} cells by metabolic stress but downregulated in those of type 2 diabetic islets that display ATF4 and HSP over-activation. Lastly, human MYT knockdown caused stress-gene over-activation and death in Endo-{beta}H1 cells. These findings suggest that the Myt TFs restrict stress-response to physiologically tolerable levels in mice and human.

developmental biology↗