thymopoietin beta; lamina-associated polypeptide 2, isoform beta; thymopoietin, isoform beta; TP beta; thymopoietin-related peptide isoform beta; TPRP isoform beta; contains: thymopoietin; TP; splenin; TP5 (TMPO, LAP2)

Function

• may help direct assembly of the nuclear lamina & thus help maintain the structural organization of the nuclear envelope
• possible receptor for attachment of lamin filaments to the inner nuclear membrane
• may be involved in the control of initiation of DNA replication through its interaction with NAKAP95
• TP & TP5 may play a role in T-cell development & function
• TP5 is an immunomodulating pentapeptide
• mitosis-specific phosphorylation specifically abolishes its binding to lamin B & chromosomes (putative)
• interacts with LMNB1, LMNB2, BANF1, AKAP8L, GMCL & chromosomes (putative)

Structure

• as two structurally independent, non-interacting domains:
  • LEM-like (also called LAP2-N or LEM-D)
    • LEM-like binds DNA
  • LEM (also called LAP2-C or LEM-B)
    • LEM interacts with BANF1
• belongs to the LEM family
• contains 1 LEM domain
• contains 1 LEM-like domain
• contains sequence for putative hydrophobic membrane spanning domain from exon 8

Compartment

• nuclear inner membrane
• single-pass type 2 membrane protein
• tightly associated with the nuclear lamina

Alternative splicing

• named isoforms=3; alpha, beta, gamma
• additional isoforms seem to exist

Expression

• expressed in many tissues
• most abundant in adult thymus & fetal liver

Pharmacology

• TP5 is available under the names Timunox (Cilag), Sintomodulina (Italofarmaco) & Mepentil (Recordati)
• used in treatment of primary & secondary immune deficiencies, autoimmunity, infections & cancer

More general terms

• thymopoietin

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=7112
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:7112
• OMIM: https://mirror.omim.org/entry/188380
• UniProt: http://www.uniprot.org/uniprot/P42167.html