Clustering protein-protein interaction data with spectral clustering and fuzzy random walk

Abstract

Spectral Clustering is a graph clustering algorithm that makes use of eigenvector obtained from a matrix describing pairwise similarity between data points. It provides a dimensionality reduction for clustering in lower dimensions. One example of spectral clustering application is the clustering of protein-protein interaction (PPI) network. PPI networks are usually represented as a graph network with proteins and interactions as vertices and edges respectively. However, this spectral clustering only produces a hard clustering of proteins, whereas there may be some relationship between each protein clusters, and possibly multiple functionality for each proteins that has not been detected before. Fuzzy Random Walk is a fuzzy clustering method based on transition probability from a random walk on a dataset. In this paper, we combine both Spectral Clustering and Fuzzy Random Walk to cluster PPI network of protein TP53, a protein thatplays an important role in managing cell cycle, especially in tumor cell suppression. Using PPI dataset of TP53 obtained from the STRING database, we found the combined algorithm is proven to produce both robust and fuzzy clusters with each cluster explains one of TP53 protein’s functionality related to the tumor cell.