ID   CAHS1_PARRC             Reviewed;         229 AA.
AC   P0CU51;
DT   07-JUN-2017, integrated into UniProtKB/Swiss-Prot.
DT   07-JUN-2017, sequence version 1.
DT   25-MAY-2022, entry version 9.
DE   RecName: Full=Cytosolic-abundant heat soluble protein 107838 {ECO:0000303|PubMed:28306513};
DE            Short=CAHS 107838 {ECO:0000303|PubMed:28306513};
DE   AltName: Full=Tardigrade-specific intrinsically disordered protein CAHS 107838 {ECO:0000303|PubMed:28306513};
DE            Short=TDP CAHS 107838 {ECO:0000303|PubMed:28306513};
GN   Name=CAHS 107838 {ECO:0000303|PubMed:28306513};
OS   Paramacrobiotus richtersi (Water bear) (Macrobiotus richtersi).
OC   Eukaryota; Metazoa; Ecdysozoa; Tardigrada; Eutardigrada; Parachela;
OC   Macrobiotoidea; Macrobiotidae; Paramacrobiotus;
OC   Paramacrobiotus richtersi group.
OX   NCBI_TaxID=697321;
RN   [1]
RP   FUNCTION.
RX   PubMed=28306513; DOI=10.1016/j.molcel.2017.02.018;
RA   Boothby T.C., Tapia H., Brozena A.H., Piszkiewicz S., Smith A.E.,
RA   Giovannini I., Rebecchi L., Pielak G.J., Koshland D., Goldstein B.;
RT   "Tardigrades use intrinsically disordered proteins to survive
RT   desiccation.";
RL   Mol. Cell 65:975-984(2017).
RN   [2]
RP   FUNCTION.
RX   PubMed=33545053; DOI=10.1016/j.molcel.2020.12.007;
RA   Arakawa K., Numata K.;
RT   "Reconsidering the 'glass transition' hypothesis of intrinsically
RT   unstructured CAHS proteins in desiccation tolerance of tardigrades.";
RL   Mol. Cell 81:409-410(2021).
CC   -!- FUNCTION: CAHS proteins are cytosolic heat soluble proteins that seem
CC       to contribute to the anhydrobiosis in tardigrades, but their specific
CC       mechanisms are yet to be identified (PubMed:28306513, PubMed:33545053).
CC       It is possible that protection during anhydrobiosis might occur via the
CC       stabilization of vitrifying small molecules such as sugars, but not via
CC       the direct glass transition of CAHS proteins themselves (Probable).
CC       {ECO:0000269|PubMed:28306513, ECO:0000269|PubMed:33545053,
CC       ECO:0000305|PubMed:33545053}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000305|PubMed:28306513}.
CC   -!- DOMAIN: CAHS proteins contain 2 repeats of 19-mer peptides designated
CC       as CAHS-motifs that comprise each two octapeptides connected by a
CC       tripeptide (By similarity). {ECO:0000250|UniProtKB:J7M799}.
CC   -!- MISCELLANEOUS: Trehalose, a disaccharide essential for several
CC       organisms to survive drying, is detected at low levels or not at all in
CC       some tardigrade species, indicating that tardigrades possess
CC       potentially novel mechanisms for surviving desiccation involving
CC       tardigrade-specific intrinsically disordered proteins (TDPs)
CC       (PubMed:28306513). {ECO:0000269|PubMed:28306513}.
CC   -!- SIMILARITY: Belongs to the Cytosolic-abundant heat soluble protein
CC       (CAHS) family. {ECO:0000305}.
CC   -!- CAUTION: It was suggested that CAHS proteins were intrinsically
CC       unstructured and show heat-dependent glass transition, which
CC       contributes to the vitrification of cells, and this further leads to
CC       desiccation tolerance (PubMed:28306513). However, more recent studies
CC       led to the conclusion that there was no evidence supporting glass
CC       transition of CAHS proteins to be contributing to the glass transition
CC       of the whole tardigrade (PubMed:33545053).
CC       {ECO:0000269|PubMed:28306513, ECO:0000269|PubMed:33545053}.
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DR   AlphaFoldDB; P0CU51; -.
DR   SMR; P0CU51; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   DisProt; DP01383; -.
PE   3: Inferred from homology;
KW   Coiled coil; Cytoplasm; Repeat; Stress response.
FT   CHAIN           1..229
FT                   /note="Cytosolic-abundant heat soluble protein 107838"
FT                   /id="PRO_0000440198"
FT   REGION          1..29
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          124..142
FT                   /note="CAHS motif 1"
FT                   /evidence="ECO:0000250|UniProtKB:J7M799"
FT   REGION          161..179
FT                   /note="CAHS motif 2"
FT                   /evidence="ECO:0000250|UniProtKB:J7M799"
FT   REGION          202..229
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COILED          109..145
FT                   /evidence="ECO:0000255"
FT   COMPBIAS        202..220
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   229 AA;  26560 MW;  5C599995774A77AA CRC64;
     MSAEAMNMNM NQDAVFIPPP EGEQYERKEK QEIQQTSYLQ SQVKVPLVNL PAPFFSTSFS
     AQEILGEGFQ ASISRISAVS EELSSIEIPE LAEEARRDFA AKTREQEMLS ANYQKEVERK
     TEAYRKQQEV EADKIRKELE KQHLRDVEFR KDIVEMAIEN QKKMIDVESR YAKKDMDRER
     VKVRMMLEQQ KFHSDIQVNL DSSAAGTETG GQVVSESQKF TERNRQIKQ