Heat Shock 70kDa Protein 5 Binding Protein 1 (HSPA5BP1)

GBP was predominantly expressed in neuronal cells among various brain tissues. GBP mRNA was already detected in the E12 brain and then gradually increased to reach a peak within P0-2 weeks after birth.

GBP expression in the brain decreased age-dependently to approximately 30% of the postnatal level at 12 months. GBP encoded 1021 amino acids and was predicted to have two transmembrane regions and glutamic acid- and proline-rich regions. Observation of COS7 cells expressing green fluorescent protein- or Myc-tagged GBP showed that GBP was localized in the endoplasmic reticulum-Golgi domain where BODIPY 558/568 (4,4-difluro-5-(2-thienyl)-4-bora-3alpha,4alpha-diaza-S-indacene)-labeled brefeldin A accumulated. GBP would have a relevant functional role in embryonic and postnatal development of the brain.