Heme Binding Protein 1 (HEBP1)

F2L is an acetylated 21-amino acid peptide derived from the N terminus of intracellular HBP. F2L bound and activated FPRL2 in the nanomolar range, triggering intracellular calcium release, inhibition of cAMP accumulation, and phosphorylation of MAP kinases. Testing on monocytes and monocyte-derived dendritic cells showed that F2L promoted calcium mobilization and chemotaxis.

Sequence analysis predicted that the 189-amino acid human HBP protein, which is 80% identical to the mouse sequence, contains a conserved hydrophobic heme-binding region not found in SOUL. Northern blot analysis detected a 1.5-kb Hbp transcript in mouse liver.