title: J domain independent functions of J proteins.
abstract: Heat shock proteins of 40 kDa (Hsp40s), also called J proteins, are obligate partners of Hsp70s. Via their highly conserved and functionally critical J domain, J proteins interact and modulate the activity of their Hsp70 partners. Mutations in the critical residues in the J domain often result in the null phenotype for the J protein in question. However, as more J proteins have been characterized, it is becoming increasingly clear that a significant number of J proteins do not "completely" rely on their J domains to carry out their cellular functions, as previously thought. In some cases, regions outside the highly conserved J domain have become more important making the J domain dispensable for some, if not for all functions of a J protein. This has profound effects on the evolution of such J proteins. Here we present selected examples of J proteins that perform J domain independent functions and discuss this in the context of evolution of J proteins with dispensable J domains and J-like proteins in eukaryotes.
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India.
authors.forename: Chetana
authors.initials: C
authors.lastname: Ajit Tamadaddi
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, India. sahi@iiserb.ac.in.
authors.forename: Chandan
authors.initials: C
authors.lastname: Sahi
mesh_terms: D000818:Animals; D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008954:Models, Biological; D017434:Protein Structure, Tertiary
chemical_list: D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins
keywords: Hsp40; Hsp70; J proteins