BAF-1 mobility is regulated by environmental stresses

Mol Biol Cell. 2014 Apr;25(7):1127-36. doi: 10.1091/mbc.E13-08-0477. Epub 2014 Feb 5.

Abstract

Barrier to autointegration factor (BAF) is an essential component of the nuclear lamina that binds lamins, LEM-domain proteins, histones, and DNA. Under normal conditions, BAF protein is highly mobile when assayed by fluorescence recovery after photobleaching and fluorescence loss in photobleaching. We report that Caenorhabditis elegans BAF-1 mobility is regulated by caloric restriction, food deprivation, and heat shock. This was not a general response of chromatin-associated proteins, as food deprivation did not affect the mobility of heterochromatin protein HPL-1 or HPL-2. Heat shock also increased the level of BAF-1 Ser-4 phosphorylation. By using missense mutations that affect BAF-1 binding to different partners we find that, overall, the ability of BAF-1 mutants to be immobilized by heat shock in intestinal cells correlated with normal or increased affinity for emerin in vitro. These results show BAF-1 localization and mobility at the nuclear lamina are regulated by stress and unexpectedly reveal BAF-1 immobilization as a specific response to caloric restriction in C. elegans intestinal cells.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / metabolism*
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism*
  • Environment*
  • Food Deprivation
  • Green Fluorescent Proteins / metabolism
  • Heat-Shock Response
  • Intestines / cytology
  • Lamins / metabolism
  • Larva / cytology
  • Larva / metabolism
  • Mass Spectrometry
  • Membrane Proteins / metabolism
  • Molecular Sequence Data
  • Mutant Proteins / metabolism
  • Mutation, Missense
  • Nuclear Proteins / metabolism
  • Phosphorylation
  • Phosphoserine / metabolism
  • Photobleaching
  • Protein Transport
  • Stress, Physiological*

Substances

  • BAF-1 protein, C elegans
  • Caenorhabditis elegans Proteins
  • Carrier Proteins
  • Lamins
  • Membrane Proteins
  • Mutant Proteins
  • Nuclear Proteins
  • emerin
  • Green Fluorescent Proteins
  • Phosphoserine