ID   2ABB_RAT                Reviewed;         443 AA.
AC   P36877; Q80W84;
DT   01-JUN-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1997, sequence version 2.
DT   04-NOV-2026, entry version 180.
DE   RecName: Full=Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B beta isoform;
DE   AltName: Full=PP2A subunit B isoform B55-beta;
DE   AltName: Full=PP2A subunit B isoform BRB;
DE   AltName: Full=PP2A subunit B isoform PR55-beta;
DE   AltName: Full=PP2A subunit B isoform R2-beta;
DE   AltName: Full=PP2A subunit B isoform beta;
GN   Name=Ppp2r2b;
OS   Rattus norvegicus (Rat).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae;
OC   Murinae; Rattus.
OX   NCBI_TaxID=10116;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
RC   STRAIN=Sprague-Dawley; TISSUE=Brain;
RX   PubMed=7607250; DOI=10.1111/j.1432-1033.1995.tb20619.x;
RA   Akiyama N., Shima H., Hatano Y., Osawa Y., Sugimura T., Nagao M.;
RT   "cDNA cloning of BR gamma, a novel brain-specific isoform of the B
RT   regulatory subunit of type-2A protein phosphatase.";
RL   Eur. J. Biochem. 230:766-772(1995).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 2), FUNCTION, INDUCTION, MUTAGENESIS OF
RP   165-ARG-ARG-166, SUBCELLULAR LOCATION, AND TISSUE SPECIFICITY.
RC   STRAIN=Sprague-Dawley; TISSUE=Brain;
RX   PubMed=12716901; DOI=10.1074/jbc.m302832200;
RA   Dagda R.K., Zaucha J.A., Wadzinski B.E., Strack S.;
RT   "A developmentally regulated, neuron-specific splice variant of the
RT   variable subunit Bbeta targets protein phosphatase 2A to mitochondria and
RT   modulates apoptosis.";
RL   J. Biol. Chem. 278:24976-24985(2003).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
RC   TISSUE=Testis;
RX   PubMed=15489334; DOI=10.1101/gr.2596504;
RG   The MGC Project Team;
RT   "The status, quality, and expansion of the NIH full-length cDNA project:
RT   the Mammalian Gene Collection (MGC).";
RL   Genome Res. 14:2121-2127(2004).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [MRNA] OF 8-177 (ISOFORM 1), AND TISSUE SPECIFICITY.
RC   TISSUE=Testis;
RX   PubMed=8389301; DOI=10.1016/0014-5793(93)81535-8;
RA   Hatano Y., Shima H., Haneji T., Miura A.B., Sugimura T., Nagao M.;
RT   "Expression of PP2A B regulatory subunit beta isotype in rat testis.";
RL   FEBS Lett. 324:71-75(1993).
RN   [5]
RP   INTERACTION WITH TOMM22, MUTAGENESIS OF ISOFORM 2, AND SUBCELLULAR
RP   LOCATION.
RX   PubMed=15923182; DOI=10.1074/jbc.m503693200;
RA   Dagda R.K., Barwacz C.A., Cribbs J.T., Strack S.;
RT   "Unfolding-resistant translocase targeting: a novel mechanism for outer
RT   mitochondrial membrane localization exemplified by the Bbeta2 regulatory
RT   subunit of protein phosphatase 2A.";
RL   J. Biol. Chem. 280:27375-27382(2005).
RN   [6]
RP   PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-275; TYR-295 AND THR-298, AND
RP   IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
RX   PubMed=16641100; DOI=10.1073/pnas.0600895103;
RA   Hoffert J.D., Pisitkun T., Wang G., Shen R.-F., Knepper M.A.;
RT   "Quantitative phosphoproteomics of vasopressin-sensitive renal cells:
RT   regulation of aquaporin-2 phosphorylation at two sites.";
RL   Proc. Natl. Acad. Sci. U.S.A. 103:7159-7164(2006).
RN   [7]
RP   FUNCTION, AND SUBCELLULAR LOCATION.
RX   PubMed=18940801; DOI=10.1074/jbc.m800989200;
RA   Dagda R.K., Merrill R.A., Cribbs J.T., Chen Y., Hell J.W., Usachev Y.M.,
RA   Strack S.;
RT   "The spinocerebellar ataxia 12 gene product and protein phosphatase 2A
RT   regulatory subunit Bbeta2 antagonizes neuronal survival by promoting
RT   mitochondrial fission.";
RL   J. Biol. Chem. 283:36241-36248(2008).
CC   -!- FUNCTION: The B regulatory subunit might modulate substrate selectivity
CC       and catalytic activity, and might also direct the localization of the
CC       catalytic enzyme to a particular subcellular compartment. Within the
CC       PP2A holoenzyme complex, isoform 2 is required to promote pro-apoptotic
CC       activity. Isoform 2 regulates neuronal survival through the
CC       mitochondrial fission and fusion balance. {ECO:0000269|PubMed:12716901,
CC       ECO:0000269|PubMed:18940801}.
CC   -!- SUBUNIT: PP2A consists of a common heterodimeric core enzyme, composed
CC       of a 36 kDa catalytic subunit (subunit C) and a 65 kDa constant
CC       regulatory subunit (PR65 or subunit A), that associates with a variety
CC       of regulatory subunits. Proteins that associate with the core dimer
CC       include three families of regulatory subunits B (the R2/B/PR55/B55,
CC       R3/B''/PR72/PR130/PR59 and R5/B'/B56 families), the 48 kDa variable
CC       regulatory subunit, viral proteins, and cell signaling molecules (By
CC       similarity). Interacts with IER5 (via N- and C-terminal regions) (By
CC       similarity). Interacts with TOMM22 (PubMed:15923182). {ECO:0000250,
CC       ECO:0000250|UniProtKB:Q00005, ECO:0000269|PubMed:15923182}.
CC   -!- SUBCELLULAR LOCATION: [Isoform 1]: Cytoplasm. Cytoplasm, cytoskeleton
CC       {ECO:0000250}. Membrane {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: [Isoform 2]: Cytoplasm. Mitochondrion.
CC       Mitochondrion outer membrane. Note=Under basal conditions, localizes to
CC       both cytosolic and mitochondrial compartments. Relocalizes from the
CC       cytosolic to the mitochondrial compartment during apoptosis. Its
CC       targeting to the outer mitochondrial membrane (OMM) involves an
CC       association with import receptors of the TOM complex and is required to
CC       promote pro-apoptotic activity.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=2;
CC       Name=1; Synonyms=Bbeta, Bbeta1;
CC         IsoId=P36877-1; Sequence=Displayed;
CC       Name=2; Synonyms=Bbeta2;
CC         IsoId=P36877-2; Sequence=VSP_037984;
CC   -!- TISSUE SPECIFICITY: Expressed in the brain. Isoform 1 and isoform 2 are
CC       expressed in the forbrain. Isoform 1 is more strongly expressed than
CC       isoform 2 in the olfactory bulb. Isoform 1 and isoform 2 are weakly
CC       expressed in the cerebellum. Isoform 1 is expressed in the testis.
CC       Isoform 2 expression is undetectable at birth rising to adult level at
CC       day 14. {ECO:0000269|PubMed:12716901, ECO:0000269|PubMed:8389301}.
CC   -!- INDUCTION: Up-regulated postnatally and in response to neuronal
CC       differentiation. {ECO:0000269|PubMed:12716901}.
CC   -!- DOMAIN: The N-terminal 26 residues of isoform 2 constitute a cryptic
CC       mitochondrial matrix import signal with critical basic and hydrophobic
CC       residues, that is necessary and sufficient for targeting the PP2A
CC       holoenzyme to the outer mitochondrial membrane (OMM) and does not
CC       affect holoenzyme formation or catalytic activity.
CC   -!- DOMAIN: The last WD repeat of isoform 2 constitutes a mitochondrial
CC       stop-transfer domain that confers resistance to the unfolding step
CC       process required for import and therefore prevents PPP2R2B matrix
CC       translocation and signal sequence cleavage.
CC   -!- MISCELLANEOUS: [Isoform 2]: Contains a cryptic mitochondrial transit
CC       peptide at positions 1-23. Mutagenesis of Lys-2 to Ala greatly reduces
CC       interaction with TOMM22, the outer mitochondrial membrane (OMM)
CC       localization and pro-apoptotic activity. Mutagenesis of Arg-6 to Ala
CC       greatly reduces outer mitochondrial membrane (OMM) localization and
CC       pro-apoptotic activity. Combined mutagenesis of Thy-7 and Leu-8 to Ala
CC       or Thy-10 and Ile-11 and Phe-12 to Ala or Ile-18 and Leu-19 to Ala
CC       strongly impaired mitochondrial localization and pro-apoptotic
CC       activity. Mutagenesis of Arg-13 to Ala does not inhibit OMM
CC       localization and pro-apoptotic activity. Mutagenesis of Cys-3 to Ala or
CC       Ser does not inhibit OMM localization and pro-apoptotic activity.
CC       Mutagenesis of Phe-4 to Ala or Thy-7 to Ala or Leu-8 to Ala or Tyr-10
CC       to Ala or Ile-11 to Ala or Phe-12 to Ala weakly impaired mitochondrial
CC       localization and pro-apoptotic activity. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the phosphatase 2A regulatory subunit B family.
CC       {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; D38260; BAA07412.1; -; mRNA.
DR   EMBL; AY251277; AAP33142.1; -; mRNA.
DR   EMBL; BC078834; AAH78834.1; -; mRNA.
DR   EMBL; D14421; BAA03313.1; -; mRNA.
DR   PIR; S33257; S33257.
DR   RefSeq; NP_001389311.1; NM_001402382.1. [P36877-1]
DR   RefSeq; NP_071545.2; NM_022209.4. [P36877-2]
DR   AlphaFoldDB; P36877; -.
DR   SMR; P36877; -.
DR   FunCoup; P36877; 1915.
DR   IntAct; P36877; 1.
DR   STRING; 10116.ENSRNOP00000071716; -.
DR   iPTMnet; P36877; -.
DR   PhosphoSitePlus; P36877; -.
DR   jPOST; P36877; -.
DR   PaxDb; 10116-ENSRNOP00000071716; -.
DR   Ensembl; ENSRNOT00000079585.3; ENSRNOP00000071824.1; ENSRNOG00000018851.9. [P36877-1]
DR   Ensembl; ENSRNOT00000131113.1; ENSRNOP00000111041.1; ENSRNOG00000018851.9. [P36877-2]
DR   Ensembl; ENSRNOT00055031785; ENSRNOP00055025701; ENSRNOG00055018620. [P36877-1]
DR   Ensembl; ENSRNOT00060019414; ENSRNOP00060015231; ENSRNOG00060011432. [P36877-1]
DR   Ensembl; ENSRNOT00065033044; ENSRNOP00065026410; ENSRNOG00065019535. [P36877-1]
DR   GeneID; 60660; -.
DR   KEGG; rno:60660; -.
DR   UCSC; RGD:631441; rat. [P36877-1]
DR   AGR; RGD:631441; -.
DR   CTD; 5521; -.
DR   RGD; 631441; Ppp2r2b.
DR   eggNOG; KOG1354; Eukaryota.
DR   GeneTree; ENSGT00950000182864; -.
DR   InParanoid; P36877; -.
DR   PRO; PR:P36877; -.
DR   Proteomes; UP000002494; Chromosome 18.
DR   Bgee; ENSRNOG00000018851; Expressed in frontal cortex and 18 other cell types or tissues.
DR   ExpressionAtlas; P36877; baseline and differential.
DR   GO; GO:0005737; C:cytoplasm; IDA:UniProtKB.
DR   GO; GO:0005856; C:cytoskeleton; IEA:UniProtKB-SubCell.
DR   GO; GO:0005829; C:cytosol; IBA:GO_Central.
DR   GO; GO:0005741; C:mitochondrial outer membrane; IDA:UniProtKB.
DR   GO; GO:0005739; C:mitochondrion; IDA:UniProtKB.
DR   GO; GO:0000159; C:protein phosphatase type 2A complex; IDA:UniProtKB.
DR   GO; GO:0019888; F:protein phosphatase regulator activity; IBA:GO_Central.
DR   GO; GO:0044877; F:protein-containing complex binding; IDA:RGD.
DR   GO; GO:0000266; P:mitochondrial fission; IDA:RGD.
DR   GO; GO:0043653; P:mitochondrial fragmentation involved in apoptotic process; IMP:RGD.
DR   GO; GO:0030182; P:neuron differentiation; IEP:RGD.
DR   GO; GO:0043525; P:positive regulation of neuron apoptotic process; IDA:UniProtKB.
DR   GO; GO:0070585; P:protein localization to mitochondrion; IMP:RGD.
DR   GO; GO:0007286; P:spermatid development; IEP:RGD.
DR   FunFam; 2.130.10.10:FF:000002; Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B; 1.
DR   Gene3D; 2.130.10.10; YVTN repeat-like/Quinoprotein amine dehydrogenase; 1.
DR   InterPro; IPR000009; PP2A_PR55.
DR   InterPro; IPR018067; PP2A_PR55_CS.
DR   InterPro; IPR015943; WD40/YVTN_repeat-like_dom_sf.
DR   InterPro; IPR036322; WD40_repeat_dom_sf.
DR   InterPro; IPR001680; WD40_rpt.
DR   PANTHER; PTHR11871; PROTEIN PHOSPHATASE PP2A REGULATORY SUBUNIT B; 1.
DR   PIRSF; PIRSF037309; PP2A_PR55; 1.
DR   PRINTS; PR00600; PP2APR55.
DR   SMART; SM00320; WD40; 6.
DR   SUPFAM; SSF50978; WD40 repeat-like; 1.
DR   PROSITE; PS01024; PR55_1; 1.
DR   PROSITE; PS01025; PR55_2; 1.
DR   PROSITE; PS00678; WD_REPEATS_1; 1.
PE   1: Evidence at protein level;
KW   Alternative splicing; Apoptosis; Cytoplasm; Cytoskeleton; Membrane;
KW   Mitochondrion; Mitochondrion outer membrane; Phosphoprotein;
KW   Reference proteome; Repeat; WD repeat.
FT   CHAIN           1..443
FT                   /note="Serine/threonine-protein phosphatase 2A 55 kDa
FT                   regulatory subunit B beta isoform"
FT                   /id="PRO_0000071427"
FT   REPEAT          22..61
FT                   /note="WD 1"
FT   REPEAT          87..128
FT                   /note="WD 2"
FT   REPEAT          171..209
FT                   /note="WD 3"
FT   REPEAT          220..260
FT                   /note="WD 4"
FT   REPEAT          279..317
FT                   /note="WD 5"
FT   REPEAT          334..375
FT                   /note="WD 6"
FT   REPEAT          410..442
FT                   /note="WD 7"
FT   MOD_RES         275
FT                   /note="Phosphoserine"
FT                   /evidence="ECO:0007744|PubMed:16641100"
FT   MOD_RES         295
FT                   /note="Phosphotyrosine"
FT                   /evidence="ECO:0007744|PubMed:16641100"
FT   MOD_RES         298
FT                   /note="Phosphothreonine"
FT                   /evidence="ECO:0007744|PubMed:16641100"
FT   VAR_SEQ         1..21
FT                   /note="MEEDIDTRKINNSFLRDHSYA -> MKCFSRYLPYIFRPPNTILSSSCH
FT                   (in isoform 2)"
FT                   /evidence="ECO:0000303|PubMed:12716901"
FT                   /id="VSP_037984"
FT   MUTAGEN         165..166
FT                   /note="RR->EE: Inhibits incorporation into the PP2A
FT                   holoenzyme complex and pro-apoptotic activity."
FT                   /evidence="ECO:0000269|PubMed:12716901"
SQ   SEQUENCE   443 AA;  51668 MW;  0089EF6E8ED53082 CRC64;
     MEEDIDTRKI NNSFLRDHSY ATEADIISTV EFNHTGELLA TGDKGGRVVI FQREQESKNQ
     VHRRGEYNVY STFQSHEPEF DYLKSLEIEE KINKIRWLPQ QNAAYFLLST NDKTVKLWKV
     SERDKRPEGY NLKDEEGRLR DPATITTLRV PVLRPMDLMV EATPRRVFAN AHTYHINSIS
     VNSDYETYMS ADDLRINLWN FEITNQSFNI VDIKPANMEE LTEVITAAEF HPHHCNTFVY
     SSSKGTIRLC DMRASALCDR HTKFFEEPED PSNRSFFSEI ISSISDVKFS HSGRYIMTRD
     YLTAKVWDLN MENRPVETYQ VHDYLRSKLC SLYENDCIFD KFECVWNGSD SVIMTGSYNN
     FFRMFDRNTK RDVTLEASRE NSKPRAILKP RKVCVGGKRR KDEISVDSLD FSKKILHTAW
     HPSENIIAVA ATNNLYIFQD KVN
//