CD50
Author: Eiji Takeuchi
Reviewers: Francisco Sanchez-Madrid, M. A. del Pozo
Link to additional info in FORUM

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OVERVIEW Molecular Families

• Families in which CD50 is a member
  • CD50-->intracellular adhesion molecule family -->immunoglobulin supergene family

Names

• CD50
• intercellular molecule-3 (ICAM-3 )

Major Links

• LocusLink: 3385
• Mendelian Inheritance in Man (OMIM): 146631
• SwissProt annotated protein record: P32942

Author's Additional Insights

• CD50 regulates leukocyte morphology
• CD50 redistributes to leukocyte uropods during cell chemotaxis and is involved in cell recruitment*

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SYSTEM VIEW Disease Relevance / Function in Vivo

• Unknown

Cellular Function

• Providing costimulatory signal in immune response
• CD50 regulates LFA-1/ICAM-1 and integrin-beta1-dependent pathways adhesion*

Cellular Expression

• Leukocytes of all lineages
• Epidermal Langerhans cells**
• Endothelial cells**
• Generally absent from cells and tissues of non-hematopoietic origin

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GENE Gene Sequence Links

• No information

Chromosomal Location

• No information

Transcription Regulating Molecules

• Unidentified molecules of 38, 70 and 125 kDa**

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TRANSCRIPT Transcript Sequence Links

• No information

Post-transcriptional Modification Link to additional info in FORUM

• Unknown

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PROTEIN Biochemical Activity

• Unknown

Protein Sequence Links

• SwissProt annotated protein record: P32942

Protein Sequence Annotation

• Type I membrane protein (518 amino acids)
• Extracellular region consists of five immunoglobulin-like domains (456 amino acids)
• 25-residue transmembrane region
• 37-residue cytoplasmic region

Protein Physical Properties

Cell_Type	MW_unreduced	MW_reduced	Comment
U937	120-140 kDa
HL60	120-140 kDa
SKW3	110-120 kDa
Jurkat	110-120 kDa
Neutrophils**	115-135 kDa

Post-translational Modification

• Fifteen potential N-glycosylation sites are in extracellular region**
• Proteolytically cleaved upon leukocyte activation**
• Phosphorylated on tyrosine and associated with tyrosine kinase activity**

Protein Structure Links

• No information

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MOLECULAR INTERACTIONS Enzymes for which this is a Substrate Link to additional info in FORUM

• Unknown

Substrates

• Unknown

Other Ligands and Associated Molecules Link to additional info in FORUM

Molecule	Comment
CD11a /CD18 (LFA-1)	LFA-1 cannot bind to CD50 without activation
Integrin alpha-d/beta2**	Integrin alpha-d/beta2 binds CD50 constitutively without requiring activation

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REAGENTS Monoclonal Antibodies

mAb	Supplier	Comment
CBR-IC3/1	de Fougerolles AR et al. 1992
HP2/19	Campanero MR et al. 1993
KS128	Fawcet J et al. 1992
BU68 (A019)	DL Hardie, Birmingham
188-2G9 (A041)	R Vilella, Barcelona
B-N2 (A064)	C Vermot-Desroches et al., Cedex
B-P12 (A069)	C Vermot-Desroches et al., Cedex
B-R1 (A070)	C Vermot-Desroches et al., Cedex
AZN-LCM3.1 (A085)	Y van Kooyk, Nijmegen
MEM171 (NL022)	V Horejsi, Praha

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REFERENCES References Link to additional info in FORUM

REVIEWS

PRIMARY CITATIONS
1. {Acevedo_A/Sanchez-Madrid_F.1993.AJP}
Acevedo A, del Pozo MA, Arroyo AG, Sanchez-Mateos P, Gonzalez-Amaro R, Sanchez-Madrid F. 1993. Distribution of ICAM-3-bearing cells in normal human tissues. Expression of a novel counter-receptor for LFA-1 in epidermal Langerhans cells. Am J Pathol 143:774-783 **
2. {Campanero_MR/Sanchez-Madrid_F.1993.JCB}
Campanero MR, del Pozo MA, Arroyo AG, Sanchez-Mateos P, Hernandez-Caselles T, Craig A, Pulido R, Sanchez-Madrid F. 1993. ICAM-3 interacts with LFA-1 and regulates the LFA-1/ICAM-1 cell adhesion pathway. J Cell Biol 123:1007-1016
3. {Fawcett_J/Simmons_DL.1992.NATUR}
Fawcett J, Holness CL, Needham LA, Turley H, Gatter KC, Mason DY, Simmons DL. 1992. Molecular cloning of ICAM-3, a third ligand for LFA-1, constitutively expressed on resting leukocytes. Nature 360:481-484
4. {Hernandez-Caselles_T/Aparicio_P.1993.EJI}
Hernandez-Caselles T, Rubio G, Campanero MR, del Pozo MA, Muro M, Sanchez-Madrid F, Aparicio P. 1993. ICAM-3, the third LFA-1 counterreceptor, is a co-stimulatory molecule for both resting and activated T lymphocytes. Eur J Immunol 23:2799-2806
5. {Juan_M/et_al.1994.JEM}
Juan M, Vinas O, Pino-Otin MR, Places L, Martinez-Caceres E, Barcelo JJ, Miralles A, Vilella R, de la Fuente MA, Vives J, et al. 1994. CD50 (intercellular adhesion molecule 3) stimulation induces calcium mobilization and tyrosine phosphorylation through p59fyn and p56lck in Jurkat T cell line. J Exp Med 179:1747-1756 **
6. {Van_der_Vieren_M/Gallatin_WM.1995.IMMUN}
Van der Vieren M, Le Trong H, Wood CL, Moore PF, St John T, Staunton DE, Gallatin WM. 1995. A novel leukointegrin, alpha d beta 2, binds preferentially to ICAM-3. Immunity 3:683-690 **
7. {Vazeux_R/Gallatin_WM.1992.NATUR}
Vazeux R, Hoffman PA, Tomita JK, Dickinson ES, Jasman RL, St John T, Gallatin WM. 1992. Cloning and characterization of a new intercellular adhesion molecule ICAM-R. Nature 360:485-488
8. {de_Fougerolles_AR/Springer_TA.1992.JEM}
de Fougerolles AR, Springer TA. 1992. Intercellular adhesion molecule 3, a third adhesion counter-receptor for lymphocyte function-associated molecule 1 on resting lymphocytes. J Exp Med 175:185-190
9. {de_Fougerolles_AR/Springer_TA.1994.JEM}
de Fougerolles AR, Qin X, Springer TA. 1994. Characterization of the function of intercellular adhesion molecule (ICAM)-3 and comparison with ICAM-1 and ICAM-2 in immune responses. J Exp Med 179:619-629
10. {del_Pozo_MA/Sanchez-Madrid_F.1995.JCB}
del Pozo MA, Sanchez-Mateos P, Nieto M, Sanchez-Madrid F. 1995. Chemokines regulate cellular polarization and adhesion receptor redistribution during lymphocyte interaction with endothelium and extracellular matrix. Involvement of cAMP signaling pathway. J Cell Biol 131:495-508 **

WWW Resources

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