The predecessor grant for this competing continuation application proposed several lines of investigation to understand the function of the novel channel/kinase protein TRPM7 (previously designated LTRPC7), and work funded under that application defined a key role for TRPM7 in regulating and/or mediating vertebrate cellular Mg2+ uptake required for cell proliferation. This competing continuation has been broadened beyond studies focused on TRPM7 to address a range of questions involving TRPM7 function and its relationship to mechanisms which regulate cellular Mg2+ homeostasis and cell growth.
In Specific Aim 1, the integration of TRPM7's Mg2+ uptake capacity with the regulation of cell growth and proliferation will be analyzed, with a focus on understanding how access to Mg2+ influences nutrient sensing translational control pathways.
Specific Aim 2 proposes studies aimed at identifying molecular and functional targets of a hypothesized signaling function of the TRPM7 kinase domain.
Sub aim 2 a) will use in vitro studies to define a preferred substrate motif and generate phosphospecific antibody reagents as an approach to identifying direct molecular targets of the kinase domain, while subaim 2b) will create and characterize """"""""analog sensitive"""""""" TRPM7 mutants for use in molecular and in-vivo approaches to identifying targets of TRPM7 kinase domain signaling function.
Specific Aim 3 will focus on characterizing the role of a novel Mg2+ transporter, designated SLC41A2, in DT40 cell Mg2+ homeostasis through the creation and characterization of an SLC41A2-deficient DT40 cell line. Together, the proposed studies will generate a foundation of knowledge on the molecular mechanisms of Mg uptake and their integration with mechanisms which regulate cell growth and proliferation. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM064316-07
Application #
7216926
Study Section
Special Emphasis Panel (ZRG1-CB-G (04))
Program Officer
Marino, Pamela
Project Start
2001-02-01
Project End
2010-03-31
Budget Start
2007-04-01
Budget End
2008-03-31
Support Year
7
Fiscal Year
2007
Total Cost
$337,539
Indirect Cost
Name
Seattle Children's Hospital
Department
Type
DUNS #
048682157
City
Seattle
State
WA
Country
United States
Zip Code
98105
Sahni, Jaya; Scharenberg, Andrew M (2013) The SLC41 family of MgtE-like magnesium transporters. Mol Aspects Med 34:620-8
Sahni, Jaya; Song, Yumei; Scharenberg, Andrew M (2012) The B. subtilis MgtE magnesium transporter can functionally compensate TRPM7-deficiency in vertebrate B-cells. PLoS One 7:e44452
Mandt, Tyler; Song, Yumei; Scharenberg, Andrew M et al. (2011) SLC41A1 Mg(2+) transport is regulated via Mg(2+)-dependent endosomal recycling through its N-terminal cytoplasmic domain. Biochem J 439:129-39
Buelow, Ben; Uzunparmak, Burak; Paddock, Marcia et al. (2009) Structure/function analysis of PARP-1 in oxidative and nitrosative stress-induced monomeric ADPR formation. PLoS One 4:e6339
Sahni, Jaya; Scharenberg, Andrew M (2008) TRPM7 ion channels are required for sustained phosphoinositide 3-kinase signaling in lymphocytes. Cell Metab 8:84-93
Scharenberg, Andrew M; Humphries, Lisa A; Rawlings, David J (2007) Calcium signalling and cell-fate choice in B cells. Nat Rev Immunol 7:778-89
Sahni, Jaya; Nelson, Bruce; Scharenberg, Andrew M (2007) SLC41A2 encodes a plasma-membrane Mg2+ transporter. Biochem J 401:505-13
Scharenberg, Andrew M (2005) TRPM2 and TRPM7: channel/enzyme fusions to generate novel intracellular sensors. Pflugers Arch 451:220-7
Schmitz, Carsten; Perraud, Anne-Laure; Fleig, Andrea et al. (2004) Dual-function ion channel/protein kinases: novel components of vertebrate magnesium regulatory mechanisms. Pediatr Res 55:734-7
Monteilh-Zoller, Mahealani K; Hermosura, Meredith C; Nadler, Monica J S et al. (2003) TRPM7 provides an ion channel mechanism for cellular entry of trace metal ions. J Gen Physiol 121:49-60

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