HSP70: Molecular Weight

The HSP70 family represents the most conserved and best characterized group of HSPs comprising polypeptides whose molecular weights range from 66 – 78 kDa and that are encoded by a multigene family encompassing up to 17 genes and 30 pseudogenes in humans ¹⁹. Functional genes encoding HSP70 proteins map to human chromosomes 6, 14, 21, and at least one other chromosome ²⁰. The most studied genes are HSPA1A and HSPA1B encoding proteins that only differ by two amino acids and are believed as being completely interchangeable proteins. The genes are clustered in the major histocompatibility complex class III region on chromosome 6p21.3.