Expression and phosphorylation of BiP/GRP78, a molecular chaperone in the endoplasmic reticulum, during the differentiation of a mouse myeloblastic cell line

Cell Struct Funct. 1995 Feb;20(1):33-9. doi: 10.1247/csf.20.33.

Abstract

To determine the functional significance of endoplasmic reticulum chaperones in hematopoietic cells, we analyzed the expression and post-translational modification of BiP/GRP78 and GRP94 as well as the cytoplasmic chaperones HSP70 and HSC70 during the differentiation of a mouse myeloid leukemia cell line, M1. The amounts of BiP/GRP78 and GRP94 increased several-fold when M1 cells were induced to differentiate into macrophage-like cells by treatment with interleukin-6 (IL-6). Synthesis began to increase at 4 hr after IL-6 treatment. The phosphorylated form of BiP/GRP78 increased during the later stages of differentiation. These data suggested that the chaperone activity of BiP/GRP78 and GRP94 may be needed for differentiated macrophage-like cells or for the differentiation event itself, and that functionally different BiP/GRP78 accumulate during the differentiation of M1 cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation / drug effects
  • Cell Line, Transformed
  • Endoplasmic Reticulum / metabolism*
  • Fungal Proteins / biosynthesis*
  • Fungal Proteins / chemistry
  • HSP70 Heat-Shock Proteins / biosynthesis*
  • HSP70 Heat-Shock Proteins / chemistry
  • Interleukin-6 / pharmacology
  • Leukemia, Myeloid / metabolism*
  • Leukemia, Myeloid / pathology
  • Macrophages / metabolism*
  • Macrophages / pathology
  • Mice
  • Molecular Chaperones / biosynthesis
  • Molecular Chaperones / chemistry
  • Phosphorylation

Substances

  • Fungal Proteins
  • HSP70 Heat-Shock Proteins
  • Interleukin-6
  • KAR2 protein, yeast
  • Molecular Chaperones