macrosialin; Gp110; CD68 (CD68)

Function

• may affect macrophage phagocytosis, both in intracellular lysosomal metabolism & extracellular cell-cell & cell-pathogen interactions
• binds to tissue- & organ-specific lectins or selectins, allowing homing of macrophage subsets to particular sites
• rapid recirculation of CD68 from endosomes, lysosomes to the plasma membrane may allow macrophages to crawl over selectin bearing substrates or other cells

Structure

• N- & O-glycosylated
• belongs to the LAMP family

Compartment

• isoform short: cell membrane
• isoform long: endosome membrane
• lysosome membrane, lysosomal

Alternative splicing

named isoforms=2; long, short

Expression

• macrophages/monocytes
• basophils
• dendritic cells
• mast cells
• myeloid cells
• CD34+ progenitor cells
• neutrophils
• osteoclasts
• activated platelets
• B cells
• T cells

Pathology

• positive staining with antibody in:
  • AML ~50% - most AML-M4, AML-M5
  • some B cell lymphomas
  • hairy cell leukemia
  • interdigitating dendritic cell sarcoma
  • Langerhans cell histiocytosis
  • mastocytosis
  • mast cell disease
  • granular cell tumors
  • occasional melanoma
  • rare granular cell type of angiosarcoma

More general terms

• CD antigen
• sialoglycoprotein
• plasma membrane protein
• lysosome-associated membrane glycoprotein (LAMP)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=968
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:968
• OMIM: https://mirror.omim.org/entry/153634
• UniProt: http://www.uniprot.org/uniprot/P34810.html