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Updated: Jun 2, 2026

Membrane-SPINE: A Biochemical Tool to Identify Protein-protein Interactions of Membrane Proteins In Vivo
Published on: November 7, 2013
MemPype: a pipeline for the annotation of eukaryotic membrane proteins
Andrea Pierleoni1, Valentina Indio, Castrense Savojardo
1Externautics s.p.a.-Bioinformatics, Via Fiorentina 1, 53100 Siena, Italy. andrea.pierleoni@externautics.com
Abstract:
MemPype is a Python-based pipeline including previously published methods for the prediction of signal peptides (SPEP), glycophosphatidylinositol (GPI) anchors (PredGPI), all-alpha membrane topology (ENSEMBLE), and a recent method (MemLoci) that specifically discriminates the localization of eukaryotic membrane proteins in: 'cell membrane', 'internal membranes', 'organelle membranes'. MemLoci scores with accuracy of 70% and generalized correlation coefficient (GCC) of 0.50 on a rigorous homology-unbiased validation set and overpasses other predictors for subcellular localization. The annotation process is based both on inheritance through homology and computational methods. Each submitted protein first retrieves, when available, up to 25 similar proteins (with sequence identity ≥50% and alignment coverage ≥50% on both sequences). This helps the identification of membrane-associated proteins and detailed localization tags. Each protein is also filtered for the presence of a GPI anchor [0.8% false positive rate (FPR)]. A positive score of GPI anchor prediction labels the sequence as exposed to 'Cell surface'. Concomitantly the sequence is analysed for the presence of a signal peptide and classified with MemLoci into one of three discriminated classes. Finally the sequence is filtered for predicting its putative all-alpha protein membrane topology (FPR <1%). The web server is available at: http://mu2py.biocomp.unibo.it/mempype.
Insights
MemPype is a novel Python pipeline for predicting eukaryotic membrane protein features. It accurately identifies signal peptides, GPI anchors, and subcellular localization, improving membrane protein annotation.
Area of Science:
- Bioinformatics
- Computational Biology
- Molecular Biology
Background:
- Accurate prediction of membrane protein characteristics is crucial for understanding cellular functions.
- Existing tools often lack comprehensive analysis for signal peptides, GPI anchors, and subcellular localization.
- Eukaryotic membrane protein annotation requires integrated approaches for reliable classification.
Purpose of the Study:
- To develop and present MemPype, an integrated Python pipeline for eukaryotic membrane protein annotation.
- To enhance the prediction accuracy of signal peptides, GPI anchors, and subcellular localization.
- To provide a user-friendly web server for computational analysis of membrane proteins.
Main Methods:
- Integration of established methods: SPEP (signal peptides), PredGPI (GPI anchors), ENSEMBL (all-alpha membrane topology).
- Inclusion of MemLoci for discriminating subcellular localization: 'cell membrane', 'internal membranes', 'organelle membranes'.
- Utilizing homology-based inheritance and computational predictions, including homology searches and filtering for specific protein features.
Main Results:
- MemLoci achieved 70% accuracy and 0.50 GCC on a homology-unbiased validation set, outperforming other predictors.
- The pipeline accurately predicts signal peptides, GPI anchors (0.8% FPR), and all-alpha membrane topology (<1% FPR).
- Homology searches (≥50% identity, ≥50% coverage) aid in identifying membrane-associated proteins and localization tags.
Conclusions:
- MemPype offers a robust and accurate pipeline for comprehensive eukaryotic membrane protein annotation.
- The integrated approach, particularly MemLoci, significantly improves subcellular localization prediction.
- The available web server facilitates accessibility and application of these advanced computational tools in biological research.
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