HGNC Approved Gene Symbol: PFN2
Cytogenetic location: 3q25.1 Genomic coordinates (GRCh38): 3:149,964,904-149,970,895 (from NCBI)
Profilin is a 14-kD protein responsible for keeping the cytoskeletal protein actin (see ACTC; 102540) monomeric under ionic conditions that promote its polymerization into filaments. Two isoforms of profilin are known: profilin-1 (PFN1; 176610) and profilin-2 (PFN2) (summary by Gieselmann et al., 1995).
By expressing both PFN1 and PFN2 in E. coli, Gieselmann et al. (1995) assessed the biochemical characteristics of the profilins and compared their interactions with poly(L-proline), phosphatidylinositol-4,5- bisphosphate, and actin. Compared to the conventional human profilin-1, profilin-2 had similar affinities for poly(L-proline) and phosphatidylinositol-4,5-bisphosphate. PFN1 and PFN2 had similar effects on nucleotide exchange by actin at low profilin-to-actin molar ratios but PFN2 had a 5-fold lower binding affinity for rabbit muscle G-actin than did PFN1.
Joensuu et al. (1996) constructed a YAC contig comprising 8.5 cM around the locus for Usher syndrome type III (USH3; 276902). (The marker D3S1319E had been mapped to 3q25-q25.2 by Naylor et al. (1996)). A BLAST search with the D3S1319E sequence revealed 2 high score homologies in opposite directions: for the ADP-ribosylation factor-1 gene (103180), which had been mapped to 1q42, showing homology of nucleotides 1 to 76; and for profilin-2, showing homology of nucleotides 305 to 374. The PCR primers used in the physical mapping of D3S1319E were derived from the profilin-2 sequences, thus suggesting that it represents a chimeric cDNA clone containing sequences from 2 genes and that they had actually localized the gene to profilin-2. This was confirmed by PCR with primers that produced an expected 101-bp fragment in the YACs positive for D3S1319E. Joensuu et al. (1996) excluded PFN2 as a USH3 candidate gene by sequencing.
Gieselmann, R., Kwiatkowski, D. J., Janmey, P. A., Witke, W. Distinct biochemical characteristics of the two human profilin isoforms. Europ. J. Biochem. 229: 621-628, 1995. [PubMed: 7758455] [Full Text: https://doi.org/10.1111/j.1432-1033.1995.tb20506.x]
Joensuu, T., Blanco, G., Pakarinen, L., Sistonen, P., Kaariainen, H., Brown, S., de la Chapelle, A., Sankila, E.-M. Refined mapping of the Usher syndrome type III locus on chromosome 3, exclusion of candidate genes, and identification of the putative mouse homologous region. Genomics 38: 255-263, 1996. [PubMed: 8975700] [Full Text: https://doi.org/10.1006/geno.1996.0626]
Kwiatkowski, D. J., Bruns, G. A. P. Human profilin: molecular cloning, sequence comparison, and chromosomal analysis. J. Biol. Chem. 263: 5910-5915, 1988. [PubMed: 3356709]
Naylor, S. L., Carritt, B., Boileau, C., Beroud, C., Alexander, C., Allderdice, P., Alimov, A., Ashworth, T., Bonifas, J., Bugert, P., Buys, C. H. C. M., Chipperfield, M. A., and 21 others. Report of the sixth international workshop on human chromosome 3 mapping. Cytogenet. Cell Genet. 72: 255-270, 1996. [PubMed: 8641130] [Full Text: https://doi.org/10.1159/000134204]