About this item:

309 Views | 229 Downloads

Author Notes:

To whom correspondence should be addressed: Dept. of Biochemistry, Emory University School of Medicine, 1510 Clifton Rd., Atlanta, GA 30322., Tel.: 404-727-5620; Fax: 404-727-2738; E-mail: dpallas@emory.edu

Both authors contributed equally to this work: Z.W. and D.S.

J. A. L., K. D. B., and D. C. P. conceptualization; J. A. L., Z. W., D. S., and D. C. P. formal analysis; J. A. L., Z. W., D. S., and D. C. P. investigation; J. A. L., Z. W., K. D. B., and D. C. P. methodology; J. A. L. and D. C. P. writing-original draft; J. A. L., Z. W., D. S., K. D. B., and D. C. P. writing-review and editing; J. A. L., Z. W., D. S., K. D. B., and D. C. P. validation; J. A. L., D. C. P., Z. W., and D. S. visualization; K. D. B. and D. C. P. resources; K. D. B. and D. C. P. supervision; K. D. B. and D. C. P. funding acquisition; K. D. B. and D. C. P. project administration.

We thank Alyssa Eidbo for technical assistance, Anya Srikureja for helping with data analysis, Tamara Caspary and Alyssa Long for helpful advice, and Anita Corbett and Rick Kahn for helpful feedback on the manuscript.

Dr. David Pallas is entitled to royalty from the sale of products related to the research described in this paper by Millipore, Inc., Santa Cruz Biotechnologies, Inc., and Novus Biologicals, Inc. In addition, Dr. David Pallas serves as a consultant to Millipore.

Subjects:

Research Funding:

Supported by National Institutes of Health Predoctoral Fellowship Grant F31CA123640 from NCI (.JA.L.).

This work was supported in part by National Institutes of Health Grant R01 CA57327 from NCI (to D. C. P.), National Institutes of Health Grant R01DK059380 (to K. D. B.), and National Institutes of Health P30CA138292 from NCI (Emory Winship Cancer Institute), and in part by the University Research Committee at Emory University (to D. C. P.) and the Aflac Cancer and Blood Disorder Center (to K. D. B. and Z. W.).

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Biochemistry & Molecular Biology
  • protein serine
  • threonine phosphatase (PSP)
  • protein phosphatase 2 (PP2A)
  • hematopoiesis
  • development
  • mouse
  • LCMT-1
  • protein phosphatase methyltransferase
  • PROTEIN PHOSPHATASE 2A
  • PP2A CATALYTIC SUBUNIT
  • BOVINE BRAIN
  • METHYL ESTERIFICATION
  • SELF-RENEWAL
  • IN-VIVO
  • SACCHAROMYCES-CEREVISIAE
  • NEUROBLASTOMA-CELLS
  • REGULATORY SUBUNITS
  • ERYTHROID-CELLS

Global loss of leucine carboxyl methyltransferase-1 causes severe defects in fetal liver hematopoiesis

Tools:

Journal Title:

Journal of Biological Chemistry

Volume:

Volume 293, Number 25

Publisher:

, Pages 9636-9650

Type of Work:

Article | Final Publisher PDF

Abstract:

Leucine carboxyl methyltransferase-1 (LCMT-1) methylates the C-terminal leucine -carboxyl group of the catalytic subunits of the protein phosphatase 2A (PP2A) subfamily of protein phosphatases, PP2Ac, PP4c, and PP6c. LCMT-1 differentially regulates the formation and function of a subset of the heterotrimeric complexes that PP2A and PP4 form with their regulatory subunits. Global LCMT-1 knockout causes embryonic lethality in mice, but LCMT-1 function in development is unknown. In this study, we analyzed the effects of global LCMT-1 loss on embryonic development. LCMT-1 knockout causes loss of PP2Ac methylation, indicating that LCMT-1 is the sole PP2Ac methyltransferase. PP2A heterotrimers containing the B and B B-type subunits are dramatically reduced in whole embryos, and the steady-state levels of PP2Ac and the PP2A structural A subunit are also down 30%. Strikingly, global loss of LCMT-1 causes severe defects in fetal hematopoiesis and usually death by embryonic day 16.5. Fetal livers of homozygous lcmt-1 knockout embryos display hypocellularity, elevated apoptosis, and greatly reduced numbers of hematopoietic stem and progenitor cell-enriched KitLinSca1 cells. The percent cycling cells and mitotic indices of WT and lcmt-1 knockout fetal liver cells are similar, suggesting that hypocellularity may be due to a combination of apoptosis and/or defects in specification, self-renewal, or survival of stem cells. Indicative of a possible intrinsic defect in stem cells, noncompetitive and competitive transplantation experiments reveal that lcmt-1 loss causes a severe multilineage hematopoietic repopulating defect. Therefore, this study reveals a novel role for LCMT-1 as a key player in fetal liver hematopoiesis.

Copyright information:

© 2018 Lee et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc.

Export to EndNote