MAPK and NF-kB cascades). Agricultural Researchers are also investigating the role of HSPs in conferring stress tolerance to hybridized plants, hoping to address drought and poor soil conditions for farming. Classification The principal heat-shock proteins that have chaperone activity belong to five conserved classes: HSP33, HSP60, HSP70/HSP110, HSP90, HSP100, and the small heat-shock proteins (sHSPs). A standard nomenclature for human HSP genes is available. Although the most important members of each family are tabulated here, some species may express additional chaperones, co-chaperones, and heat shock proteins not listed. In addition, many of these proteins may have multiple splice variants (Hsp90α and Hsp90β, for instance) or conflicts of nomenclature (Hsp72 is sometimes called Hsp70). See also Cellular stress response Chaperone Chaperonin Co-chaperone FourU thermometer Hsp90 cis-regulatory element ROSE element HSF1 References External links