RRC ID 49717
Author Tanaka S, Tanaka J, Miwa Y, Horikawa DD, Katayama T, Arakawa K, Toyoda A, Kubo T, Kunieda T.
Title Novel mitochondria-targeted heat-soluble proteins identified in the anhydrobiotic Tardigrade improve osmotic tolerance of human cells.
Journal PLoS One
Abstract Tardigrades are able to tolerate almost complete dehydration through transition to a metabolically inactive state, called "anhydrobiosis". Late Embryogenesis Abundant (LEA) proteins are heat-soluble proteins involved in the desiccation tolerance of many anhydrobiotic organisms. Tardigrades, Ramazzottius varieornatus, however, express predominantly tardigrade-unique heat-soluble proteins: CAHS (Cytoplasmic Abundant Heat Soluble) and SAHS (Secretory Abundant Heat Soluble) proteins, which are secreted or localized in most intracellular compartments, except the mitochondria. Although mitochondrial integrity is crucial to ensure cellular survival, protective molecules for mitochondria have remained elusive. Here, we identified two novel mitochondrial heat-soluble proteins, RvLEAM and MAHS (Mitochondrial Abundant Heat Soluble), as potent mitochondrial protectants from Ramazzottius varieornatus. RvLEAM is a group3 LEA protein and immunohistochemistry confirmed its mitochondrial localization in tardigrade cells. MAHS-green fluorescent protein fusion protein localized in human mitochondria and was heat-soluble in vitro, though no sequence similarity with other known proteins was found, and one region was conserved among tardigrades. Furthermore, we demonstrated that RvLEAM protein as well as MAHS protein improved the hyperosmotic tolerance of human cells. The findings of the present study revealed that tardigrade mitochondria contain at least two types of heat-soluble proteins that might have protective roles in water-deficient environments.
Volume 10(2)
Pages e0118272
Published 2015-1-1
DOI 10.1371/journal.pone.0118272
PII PONE-D-14-44351
PMID 25675104
PMC PMC4326354
MeSH Amino Acid Motifs Amino Acid Sequence Animals Hot Temperature Humans Mitochondria / metabolism Mitochondrial Proteins / chemistry Mitochondrial Proteins / genetics Mitochondrial Proteins / metabolism* Molecular Sequence Data Osmoregulation* / genetics Osmotic Pressure* Protein Transport Solubility Tardigrada / physiology*
IF 2.74
Times Cited 27
DNA material pEThT-MAHS delta MTP (RDB14653) pEThT-RvLEAM (RDB14654).
Human and Animal Cells HEp-2(RCB1889) 293T(RCB2202)