Drosophila Small Heat Shock Proteins: An Update on Their Features and Functions

Abstract

Small heat shock proteins (sHsps) are present in varying numbers in all organisms. In Drosophila melanogaster there are 12 sHsps, which have distinctive developmental expression patterns, intracellular localizations and substrate specificities. Even if most of Drosophila sHsps do not have a known mammalian ortholog, they share their involvement in multiple cellular processes such as cytoskeleton modulation, apoptosis and autophagy. New data on Drosophila sHsps have arisen from high-throughput genomic and proteomic studies as well as from deletion experiments. In addition to showing the complexity of this family, these experiments suggest the involvement of sHsps in new cellular processes such as the involvement of Hsp27 in piRNA biosynthesis. The goal of this review is to summarize the new findings on each Drosophila sHsp and to highlight its similarity to other sHsps as well as its distinctive features.