CD13
Author: Sanna M. Goyert
Reviewer: Erna Moller
Link to additional info in FORUM

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OVERVIEW Molecular Families

• Families in which CD13 is a member
  • CD13-->peptidase M1 -->zinc metallopeptidase -->peptidases classified by active site -->peptidases -->top node family

Names

• CD13
• Aminopeptidase N (APN )
• EC 3.4.11.2
• gp150

Major Links

• LocusLink: 290
• Mendelian Inheritance in Man (OMIM): 151530
• SwissProt annotated protein record: P15144

Author's Additional Insights

• The gene is located on chromosome 15 at q25-q26

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SYSTEM VIEW Disease Relevance / Function in Vivo

• Acts as a receptor for specific strains of RNA viruses (coronaviruses) which cause a relatively large percentage of upper respiratory trace infections
• CD13 serves an important function for the early events in the interaction between human cytomegalovirus (CMV) and the target cells. CMV incorporates the cellular CD13 protein in its envelope. In certain immunocompromised patients a CMV infection induces a CD13-specific antibody response. The presence of CD13-autoantibodies is strongly associated with the development of chronic graft versus host disease (GVHD) following bone marrow transplantation**

Cellular Function

• No information

Cellular Expression

• Expressed on the surface of early committed progenitors of granulocytes and monocytes (CFU-GM) and by all cells of these lineages as they mature
• Expressed on endothelial cells, epithelial cells from renal proximal tubules and intestinal brush border, bone marrow stromal cells, osteoclasts, and cells lining bile duct canaliculi
• Expressed on a small proportion of large granular lymphocytes (Soderberg et al 1993) but not other lymphocytes*

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GENE Gene Sequence Links

• No information

Chromosomal Location

• No information

Transcription Regulating Molecules

• No information in table

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TRANSCRIPT Transcript Sequence Links

• No information

Post-transcriptional Modification

• No information

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PROTEIN Biochemical Activity

• Functional studies show that CD13/APN catalyzes the removal of single amino acids from the amino terminus of small peptides and probably plays a role in their final digestion
• CD13 participates in trimming peptides bound to MHC class II molecules (Larsen et al. 1996)**
• CD13 cleaves MIP-1 chemokine, which alters target cell specificity from basophils to eosinophils (Weber et al 1996)**

Protein Sequence Links

• SwissProt annotated protein record: P15144

Protein Sequence Annotation

• CD13 is a Type II integral membrane protein composed of 967 amino acids
• 10 sites for N-linked glycosylation
• Abundant sites for O-linked glycosylation
• The mature form of CD13 is expressed on the cell surface as a homodimer*
• CD13 is identical in structure to aminopeptidase N, a membrane bound zinc-binding metalloprotease which degrades regulatory peptides produced by diverse cell types

Protein Physical Properties

Cell_Type	MW_unreduced	MW_reduced	Comment
Unspecified	150 kDa

Post-translational Modification

• Highly glycosylated
• Variations in O-linked glycosylation produces different epitopes effecting mAb recognition

Protein Structure Links

• No information

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MOLECULAR INTERACTIONS Enzymes for which this is a Substrate

• No information in table

Substrates Link to additional info in FORUM

• No information in table

Other Ligands and Associated Molecules

• No information in table

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REAGENTS Monoclonal Antibodies

mAb	Supplier	Comment
MCS-2 (MR17)	Look AT et al. 1989
72a (MR21)
7H5 (M50)	Hristo Taskov, Bulgaria
X13 (MA45)	J Hinrich Peters, Germany

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REFERENCES References

REVIEWS

PRIMARY CITATIONS
1. {Larsen_SL/Stryhn_A.1996.JEM}
Larsen SL, Pedersen LO, Buus S, Stryhn A. 1996. T cell responses affected by aminopeptidase N (CD13)-mediated trimming of major histocompatibility complex class II-bound peptides. J Exp Med 184:183-189 **
2. {Look_AT/Peiper_SC.1989.JCI}
Look AT, Ashmun RA, Shapiro LH, Peiper SC. 1989. Human myeloid plasma membrane glycoprotein CD13 (gp150) is identical to aminopeptidase N. J Clin Invest 83:1299-1307
3. {No_Authors.}
Ashmun, R.A., Holmes, K.V., Shapiro, L.H., et al. Leukocyte Typing III (ed.771-774)
4. {Olsen_J/et_al.1988.FL}
Olsen J, Cowell GM, Konigshofer E, Danielsen EM, Moller J, Laustsen L, Hansen OC, Welinder KG, Engberg J, Hunziker W, et al. 1988. Complete amino acid sequence of human intestinal aminopeptidase N as deduced from cloned cDNA. FEBS Lett 238:307-314
5. {Semenza_G.1986.ARCB}
Semenza G. 1986. Anchoring and biosynthesis of stalked brush border membrane proteins: glycosidases and peptidases of enterocytes and renal tubuli. Annu Rev Cell Biol 2:255-313
6. {Soderberg_C/Moller_E.1993.JV}
Soderberg C, Giugni TD, Zaia JA, Larsson S, Wahlberg JM, Moller E. 1993. CD13 (human aminopeptidase N) mediates human cytomegalovirus infection. J Virol 67:6576-6585 **
7. {Soderberg_C/Moller_E.1996.TRANS}
Soderberg C, Larsson S, Rozell BL, Sumitran-Karuppan S, Ljungman P, Moller E. 1996. Cytomegalovirus-induced CD13-specific autoimmunity--a possible cause of chronic graft-vs-host disease. Transplantation 61:600-609
8. {Weber_M/Dahinden_CA.1996.JEM}
Weber M, Uguccioni M, Baggiolini M, Clark-Lewis I, Dahinden CA. 1996. Deletion of the NH2-terminal residue converts monocyte chemotactic protein 1 from an activator of basophil mediator release to an eosinophil chemoattractant. J Exp Med 183:681-685 **
9. {Yeager_CL/Holmes_KV.1992.NATUR}
Yeager CL, Ashmun RA, Williams RK, Cardellichio CB, Shapiro LH, Look AT, Holmes KV. 1992. Human aminopeptidase N is a receptor for human coronavirus 229E. Nature 357:420-422

WWW Resources

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* indicates amended by reviewer, ** indicates added by reviewer
Modified 10/14/99 mpr@mail.nih.gov