Seroatlas · Human Serome Atlas

SUN2

SUN domain-containing protein 2

Also known as: SUN2_HUMAN, UNC84B

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q9UH99
Gene
SUN2
Ensembl
ENSG00000100242
Chromosome
22
Canonical length
717 aa
Protein class
Plasma proteins, Predicted intracellular proteins, Predicted membrane proteins, Transporters
Subcellular location
Nuclear membrane

OverviewNCBI Gene

SUN1 (MIM 607723) and SUN2 are inner nuclear membrane (INM) proteins that play a major role in nuclear-cytoplasmic connection by formation of a 'bridge' across the nuclear envelope, known as the LINC complex, via interaction with the conserved luminal KASH domain of nesprins (e.g., SYNE1; MIM 608441) located in the outer nuclear membrane (ONM). The LINC complex provides a direct connection between the nuclear lamina and the cytoskeleton, which contributes to nuclear positioning and cellular rigidity (summary by Haque et al., 2010 [PubMed 19933576]).[supplied by OMIM, Nov 2010]

Canonical amino-acid sequenceUniProt

717 residues, UniProt reviewed canonical sequence.

>Q9UH99|SUN2
     1  MSRRSQRLTR YSQGDDDGSS SSGGSSVAGS QSTLFKDSPL RTLKRKSSNM KRLSPAPQLG
    61  PSSDAHTSYY SESLVHESWF PPRSSLEELH GDANWGEDLR VRRRRGTGGS ESSRASGLVG
   121  RKATEDFLGS SSGYSSEDDY VGYSDVDQQS SSSRLRSAVS RAGSLLWMVA TSPGRLFRLL
   181  YWWAGTTWYR LTTAASLLDV FVLTRRFSSL KTFLWFLLPL LLLTCLTYGA WYFYPYGLQT
   241  FHPALVSWWA AKDSRRPDEG WEARDSSPHF QAEQRVMSRV HSLERRLEAL AAEFSSNWQK
   301  EAMRLERLEL RQGAPGQGGG GGLSHEDTLA LLEGLVSRRE AALKEDFRRE TAARIQEELS
   361  ALRAEHQQDS EDLFKKIVRA SQESEARIQQ LKSEWQSMTQ ESFQESSVKE LRRLEDQLAG
   421  LQQELAALAL KQSSVAEEVG LLPQQIQAVR DDVESQFPAW ISQFLARGGG GRVGLLQREE
   481  MQAQLRELES KILTHVAEMQ GKSAREAAAS LSLTLQKEGV IGVTEEQVHH IVKQALQRYS
   541  EDRIGLADYA LESGGASVIS TRCSETYETK TALLSLFGIP LWYHSQSPRV ILQPDVHPGN
   601  CWAFQGPQGF AVVRLSARIR PTAVTLEHVP KALSPNSTIS SAPKDFAIFG FDEDLQQEGT
   661  LLGKFTYDQD GEPIQTFHFQ APTMATYQVV ELRILTNWGH PEYTCIYRFR VHGEPAH

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SUN2 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Other membrane
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.51
Highest tissue expression
122 nTPM

Expression across tissuesHPA

Tissue

  • bone marrow: 122 nTPM
  • adipose tissue: 97 nTPM
  • lymph node: 89 nTPM
  • spleen: 69 nTPM
  • liver: 68 nTPM
  • pancreas: 66 nTPM

Single-cell type

  • epicardial cells: 425 nCPM
  • oligodendrocytes: 236 nCPM
  • esophageal apical cells: 183 nCPM
  • nk-cells: 176 nCPM
  • neutrophils: 174 nCPM
  • hepatocytes: 139 nCPM

Immune cell

  • gdT-cell: 41 nTPM
  • memory CD8 T-cell: 34 nTPM
  • naive CD8 T-cell: 32 nTPM
  • basophil: 28 nTPM
  • MAIT T-cell: 27 nTPM
  • naive CD4 T-cell: 26 nTPM

Brain region

  • white matter: 442 nTPM
  • basal ganglia: 396 nTPM
  • medulla oblongata: 340 nTPM
  • midbrain: 337 nTPM
  • pons: 311 nTPM
  • thalamus: 298 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.65
gnomAD pLI
0
gnomAD missense Z
0.95
DepMap mean gene effect
-0.01
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SUN2 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SUN2 as an antibody target. Whether an autoantibody or antibody against SUN2 could matter depends on whether native SUN2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SUN2 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label SUN2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SUN2. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...