Go to JCI Insight
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Alerts
  • Advertising
  • Job board
  • Subscribe
  • Contact
  • Current issue
  • Past issues
  • By specialty
    • COVID-19
    • Cardiology
    • Gastroenterology
    • Immunology
    • Metabolism
    • Nephrology
    • Neuroscience
    • Oncology
    • Pulmonology
    • Vascular biology
    • All ...
  • Videos
    • Conversations with Giants in Medicine
    • Author's Takes
  • Reviews
    • View all reviews ...
    • Aging (Upcoming)
    • Next-Generation Sequencing in Medicine (Jun 2022)
    • New Therapeutic Targets in Cardiovascular Diseases (Mar 2022)
    • Immunometabolism (Jan 2022)
    • Circadian Rhythm (Oct 2021)
    • Gut-Brain Axis (Jul 2021)
    • Tumor Microenvironment (Mar 2021)
    • View all review series ...
  • Viewpoint
  • Collections
    • In-Press Preview
    • Commentaries
    • Concise Communication
    • Editorials
    • Viewpoint
    • Top read articles
  • Clinical Medicine
  • JCI This Month
    • Current issue
    • Past issues

  • Current issue
  • Past issues
  • Specialties
  • Reviews
  • Review series
  • Conversations with Giants in Medicine
  • Author's Takes
  • In-Press Preview
  • Commentaries
  • Concise Communication
  • Editorials
  • Viewpoint
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Publication ethics
  • Alerts
  • Advertising
  • Job board
  • Subscribe
  • Contact
Tescalcin is an essential factor in megakaryocytic differentiation associated with Ets family gene expression
Konstantin Levay, Vladlen Z. Slepak
Konstantin Levay, Vladlen Z. Slepak
Published September 4, 2007
Citation Information: J Clin Invest. 2007;117(9):2672-2683. https://doi.org/10.1172/JCI27465.
View: Text | PDF
Research Article Hematology

Tescalcin is an essential factor in megakaryocytic differentiation associated with Ets family gene expression

  • Text
  • PDF
Abstract

We show here that the process of megakaryocytic differentiation requires the presence of the recently discovered protein tescalcin. Tescalcin is dramatically upregulated during the differentiation and maturation of primary megakaryocytes or upon PMA-induced differentiation of K562 cells. This upregulation requires sustained signaling through the ERK pathway. Overexpression of tescalcin in K562 cells initiates events of spontaneous megakaryocytic differentiation, such as expression of specific cell surface antigens, inhibition of cell proliferation, and polyploidization. Conversely, knockdown of this protein in primary CD34+ hematopoietic progenitors and cell lines by RNA interference suppresses megakaryocytic differentiation. In cells lacking tescalcin, the expression of Fli-1, Ets-1, and Ets-2 transcription factors, but not GATA-1 or MafB, is blocked. Thus, tescalcin is essential for the coupling of ERK cascade activation with the expression of Ets family genes in megakaryocytic differentiation.

Authors

Konstantin Levay, Vladlen Z. Slepak

×

Figure 1

The expression of tescalcin is increased during megakaryocytic differentiation.

Options: View larger image (or click on image) Download as PowerPoint
The expression of tescalcin is increased during megakaryocytic different...
(A) K562 cells were cultured in the presence of DMSO, hemin, or PMA for 72 hours, as described in Methods. Cells lysates were subjected to Western blot analysis with antibody against tescalcin. (B) Stimulation with PMA upregulates tescalcin at the mRNA level. K562 and HEL cells were cultured in the absence or presence of PMA for 72 hours. Total RNA subjected to quantitative RQ-PCR with tescalcin-specific primers (TaqMan). Obtained values (n = 3; mean ± SD) were normalized to 18S ribosomal RNA, and expressed relative to unstimulated K562. (C) Tescalcin expression in primary MKs. Mature mouse MKs were obtained from fetal livers as described in Methods. Lysates of fetal liver cells (FLC) and MKs were analyzed for tescalcin expression by Western blot. K562 lysate was used as positive control. (D) K562 cells were cultured in the presence of PMA (10 nM) for the indicated times, and the accumulation of tescalcin was determined by Western blot. (E) Bryostatin blocks PMA-induced upregulation of tescalcin. K562 cells were stimulated by 10 nM PMA in the absence or presence of 100 nM bryostatin (Bryo). The expression of tescalcin was determined by Western blot. (F) Sustained ERK activity is required for tescalcin upregulation. K562 cells were stimulated by PMA (10 nM) in the absence or presence of MEK1/2 inhibitor (20 μM; U0126). Cell lysates were probed with antibodies to tescalcin, total p44/42 MAPKs (ERK1/2), and phospho-p44/42 MAP kinases (ERK1*/2*).

Copyright © 2022 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)

Sign up for email alerts