Dataset Information

Cx37 Phosphorylation and cell cycle regulation

ABSTRACT: Using alanine and aspartate substitutions to mimic dephosphorylated and phosphorylated Cx37, respectively, we showed that induced expression of Cx37 in rat insulinoma cells could arrest cell cycle progression, support cell cycle progression or cause cell death in a phosphosite specific manner. In the current study, we induced Cx37 expression for 24h in 80-90% confluent Rin cells, which arrests their proliferation for many days, and determined by mass spectrometry which sites in Cx37 were phosphorylated under control conditions, following stimulation of PKC with phorbol ester, or following inhibition of PKC with bis-indolylmaleimide. The results consistently showed phosphorylation of serine 319, a high probability target for CMGC kinases. Serines 275, 321 and 328 were also identified as phosphorylated residues; these sites are also high probability targets of growth factor activated kinases. No quantitative differences between treatment groups were identified. Since growth arrest was the phenotype displayed by the cells from which the Cx37 isolated, it seems likely that S319, when phosphorylated, promotes growth arrest. Single site mutations of Serines 275, 321 and 328 also alter growth phenotype: S275D induces cell death at low cell densities but has no detectable effect on Rin cell proliferation at high cell densities; S321D induces cell death at all cell densities; and both S328A and S238D induce cell death at all densities. These results support the conclusion that Cx37 regulates growth phenotype in a phosphorylation-site specific manner and suggest that intra-molecular interactions are modulated by differential phosphorylation in the carboxy terminal domain.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Pancreatic Endocrine Cell

DISEASE(S): Pancreatic Cancer

SUBMITTER: Paul Langlais

LAB HEAD: Paul R. Langlais

PROVIDER: PXD012191 | Pride | 2019-02-13

REPOSITORIES: Pride

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			Action	DRS
	20180710_C3P0_4095_1.raw	Raw
	20180710_C3P0_4095_1.raw (F004916).mzid_20180710_C3P0_4095_1.raw_(F004916).pride.mgf.gz	Mzid
	20180710_C3P0_4095_1.raw (F004916).pride.mztab.gz	Mztab
	20180710_C3P0_4095_1.rawF004916.mzid.gz	Mzid
	20180710_C3P0_4095_1.rawF004916.mzid_20180710_C3P0_4095_1.raw_F004916.MGF	Mzid

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Publications

Phosphorylation-Dependent Intra-Domain Interaction of the Cx37 Carboxyl-Terminus Controls Cell Survival.

Jacobsen Nicole L NL Pontifex Tasha K TK Langlais Paul R PR Burt Janis M JM

Cancers 20190206 2

Differential phosphorylation of the carboxyl-terminus of connexin 37 (Cx37-CT) regulates phenotypic switching between cell growth phenotypes (cell death, cell cycle arrest, proliferation). The specific phosphorylation events in the Cx37-CT that are necessary for these growth regulatory effects are currently unknown. Through the combined use of deletion and site specific (de)phospho-mimetic Cx37-CT mutants, our data suggest a phosphorylation-dependent interaction between the mid-tail (aa 273⁻317) ...[more]

PMID: 30736283

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