Phosphorylation of the adaptor protein SH2B1β regulates its ability to enhance growth hormonedependent macrophage motility

Hsiao Wen Su, Nathan J. Lanning, David L. Morris, Lawrence S. Argetsinger, Carey N. Lumeng, Christin Carter-Su

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

Previous studies have shown that growth hormone (GH) recruits the adapter protein SH2B1b to the GH-activated, GH receptorassociated tyrosine kinase JAK2, implicating SH2B1b in GH-dependent actin cytoskeleton remodeling, and suggesting that phosphorylation at serines 161 and 165 in SH2B1b releases SH2B1b from the plasma membrane. Here, we examined the role of SH2B1b in GH regulation of macrophage migration. We show that GH stimulates migration of cultured RAW264.7 macrophages, and primary cultures of peritoneal and bone marrow-derived macrophages. SH2B1b overexpression enhances, whereas SH2B1 knockdown inhibits, GH-dependent motility of RAW macrophages. At least two independent mechanisms regulate the SH2B1b-mediated changes in motility. In response to GH, tyrosines 439 and 494 in SH2B1b are phosphorylated. Mutating these tyrosines in SH2B1b decreases both basal and GH-stimulated macrophage migration. In addition, mutating the polybasic nuclear localization sequence (NLS) in SH2B1b or creating the phosphomimetics SH2B1b(S161E) or SH2B1b(S165E), all of which release SH2B1b from the plasma membrane, enhances macrophage motility. Conversely, SH2B1b(S161/165A) exhibits increased localization at the plasma membrane and decreased macrophage migration. Mutating the NLS or the nearby serine residues does not alter GH-dependent phosphorylation on tyrosines 439 and 494 in SH2B1b. Mutating tyrosines 439 and 494 does not affect localization of SH2B1b at the plasma membrane or movement of SH2B1b into focal adhesions. Taken together, these results suggest that SH2B1b enhances GH-stimulated macrophage motility via mechanisms involving phosphorylation of SH2B1b on tyrosines 439 and 494 and movement of SH2B1b out of the plasma membrane (e.g. as a result of phosphorylation of serines 161 and 165).

Original languageEnglish (US)
Pages (from-to)1733-1743
Number of pages11
JournalJournal of cell science
Volume126
Issue number8
DOIs
StatePublished - Apr 15 2013

Keywords

  • Growth hormone
  • Macrophage
  • Motility
  • Phosphorylation
  • SH2B1

ASJC Scopus subject areas

  • Cell Biology

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    Su, H. W., Lanning, N. J., Morris, D. L., Argetsinger, L. S., Lumeng, C. N., & Carter-Su, C. (2013). Phosphorylation of the adaptor protein SH2B1β regulates its ability to enhance growth hormonedependent macrophage motility. Journal of cell science, 126(8), 1733-1743. https://doi.org/10.1242/jcs.113050