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Updated: May 24, 2026
09:40
Analysis of the c-KIT Ligand Promoter Using Chromatin Immunoprecipitation
Published on: June 27, 2017
Rab27b regulates c-kit expression by controlling the secretion of stem cell factor
Chisato Tanaka1, Hiroaki Kaji, Jinsong He
1Division of Epidemiology, Department of Community Medicine and Social Healthcare Science, Kobe University Graduate School of Medicine, Kobe, Japan.
Biochemical and Biophysical Research Communications
|February 22, 2012
Summary
Rab27b negatively regulates c-kit expression in megakaryocytes by controlling stem cell factor (SCF) secretion. Reduced Rab27b leads to increased c-kit levels, impacting cell signaling pathways.
Area of Science:
- Cell Biology
- Hematopoiesis
- Molecular Biology
Background:
- Rab27b, a small GTPase, is known in platelets but its function in megakaryocytic cells is unclear.
- Understanding Rab27b's role is crucial for megakaryopoiesis and platelet production.
Purpose of the Study:
- To investigate the function of Rab27b in megakaryocytic lineage cells.
- To elucidate the regulatory mechanism of c-kit expression by Rab27b.
Main Methods:
- Utilized a human megakaryoblastic cell line (CMK).
- Employed shRNA-mediated knockdown of Rab27b.
- Analyzed c-kit expression and degradation dynamics upon stem cell factor (SCF) stimulation.
- Investigated the role of the endolysosomal degradation system and SCF secretion.
Main Results:
- Rab27b knockdown in CMK cells significantly increased c-kit expression.
- SCF stimulation led to rapid reduction and degradation of cell surface c-kit.
- Lysosome inhibitor bafilomycin suppressed c-kit degradation, confirming endolysosomal involvement.
- Rab27b knockdown reduced autocrine SCF secretion.
Conclusions:
- Rab27b negatively regulates cell surface c-kit expression in megakaryocytic cells.
- This regulation occurs via modulation of SCF secretion and subsequent SCF-induced endolysosomal degradation of c-kit.
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