CD34; hematopoietic progenitor cell antigen CD34 (CD34)

Function

• endothelial cell receptor that binds to L-selectin on neutrophils during adhesion process
• possible adhesion molecule with a role in early hematopoiesis by mediating the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells
• could act as a scaffold for attachment of lineage specific glycans, allowing stem cells to bind to lectins expressed by stromal cells or other marrow components
• presents carbohydrate ligands to selectins
• phosphorylated on serine residues by PKC

Structure

• highly glycosylated
• belongs to the CD34 family

Compartment

cell membrane, cell surface

Alternative splicing

named isoforms=2

Expression

• selectively expressed on hematopoietic progenitor cells & vascular endothelial cells
• expressed on early hematopoietic progenitor cells

Pathology

• expressed in:
  • leukemic blasts, 40% AML, 75% pre-B ALL, most AML-M7
  • vascular neoplasms
  • hemangiopericytomas ~50%
  • epithelioid sarcomas
  • dermatofibrosarcoma protuberans
  • solitary fibrous tumors
  • nuchal fibromas
  • spindle cell lipoma
  • neurofibromas
  • schwannomas
  • malignant peripheral nerve sheath tumors (variable)
  • gastrointestinal stromal tumors
  • granulocytic sarcomas
  • Kaposi's sarcoma

More general terms

• CD antigen
• glycoprotein
• phosphoprotein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:947
• OMIM: https://mirror.omim.org/entry/142230
• UniProt: http://www.uniprot.org/uniprot/P28906.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=947