On the origin and evolution of vertebrate and viral profilins

Abstract

The three dimensional structures of profilins from invertebrates and vertebrates are remarkably similar despite low sequence similarity. Their evolutionary relationship remains thus enigmatic. A phylogenetic analysis of profilins from Deuterostoma indicates that profilin III and IV isoforms each form distinct groups. Profilin IV is most related to invertebrate profilins and originated prior to vertebrate evolution whereas separation of profilin I, II and III isoforms occurred early in vertebrate evolution. Viral profilins are most similar to profilin III. In silico analysis of representative profilin gene structures corroborates the phylogenetic result and we discuss this in terms of biochemical differences.

Structural, Functional, and Immunological Characterization of Profilin Panallergens Amb a 8, Art v 4, and Bet v 2

“…invertebrates and vertebral profilin 4 due to their relatively high sequence similarity to allergenic plant profilins) should also be identified as allergens. Our clustering results are in agreement with previous studies of evolutionary origins of profilins showing that profilins 4 are most similar to invertebrate profilins and originated before vertebrate evolution (13). The proteins that were investigated here (Amb a 8.0101, Art v 4.0101, and Bet v 2.0101) have relatively low levels of sequence identity and similarity when compared with human profilins, and this fact correlates well with the presence of a separate cluster containing human proteins (Vertebrata 1-3) and other vertebrate profilins 1, 2, and 3.…”

“…The profilin family shares highly conserved amino acid sequences that, in some instances, have over 75% identity, even between distantly related sources. Based on their source, profilins are described as originating from mammals, plants, other eukaryotes, and viruses (13). Plant profilins can be further divided into pollens, food, and products.…”

Epigenetic regulation of Smad2 and Smad3 by profilin-2 promotes lung cancer growth and metastasis

“…Because profilin-2b is a rare variant, the profilin-2 used in our investigation is profilin-2a. The alternative splicing C terminus of profilin-2 is relatively conserved and may be responsible for its distinct biological functions 13,35 . Thus, we next examined whether the C terminus of profilin-2 is essential for its binding with HDAC1.…”

“…Profilin-1 (Pfn1) and profilin-2 (Pfn2) are the most abundant profilins in mammalian cells. These two profilin variants have similar actin monomer-binding properties 13 . In the presence of formin, profilin promotes the elongation of the uncapped barbed end of the actin filament.…”

In birds, profilin-2a is ubiquitously expressed and contributes to actin-based motility

“…Consistent with such a concept is the notion that profilins occur in a number of isoforms that show tissue-specific expression. The structural relationship and evolutionary origin of profilin isoforms and paralogues from vertebrates has been investigated in detail (Polet et al, 2007), but their biochemical and cell biological properties has been analyzed only in a restricted number of cases. In mammals, four discrete profilin genes, one of which is spliced in two ways, give rise to five different isoforms.…”