Nesprin-1alpha self-associates and binds directly to emerin and lamin A in vitro

FEBS Lett. 2002 Aug 14;525(1-3):135-40. doi: 10.1016/s0014-5793(02)03105-8.

Abstract

Nesprin-1alpha is a spectrin repeat (SR)-containing, transmembrane protein of the inner nuclear membrane, and is highly expressed in muscle cells. A yeast two-hybrid screen for nesprin-1alpha-interacting proteins showed that nesprin-1alpha interacted with itself. Blot overlay experiments revealed that nesprin-1alpha's third SR binds the fifth SR. The carboxy-terminal half of nesprin-1alpha directly bound lamin A, a nuclear intermediate filament protein. Biochemical analysis demonstrated that nesprin-1alpha dimers bind directly to the nucleoplasmic domain of emerin, an inner nuclear membrane protein, with an affinity of 4 nM. Binding was optimal for full nucleoplasmic dimers of nesprin-1alpha, since nesprin fragments SR1-5 and SR5-7 bound emerin as monomers with affinities of 53 nM and 250 mM, respectively. We propose that membrane-anchored nesprin-1alpha antiparallel dimers interact with both emerin and lamin A to provide scaffolding at the inner nuclear membrane.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Carrier Proteins / metabolism*
  • Cytoskeletal Proteins
  • DNA-Binding Proteins / metabolism
  • Dimerization
  • Humans
  • Lamin Type A
  • Lamins
  • Membrane Proteins / metabolism*
  • Nerve Tissue Proteins*
  • Nuclear Envelope / metabolism
  • Nuclear Proteins / metabolism*
  • Peptide Fragments / metabolism
  • Protein Binding / physiology
  • Protein Structure, Tertiary / physiology
  • RNA-Binding Proteins
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins*
  • Thymopoietins / metabolism*
  • Transcription Factors / metabolism
  • Two-Hybrid System Techniques

Substances

  • ABF1 protein, S cerevisiae
  • Carrier Proteins
  • Cytoskeletal Proteins
  • DNA-Binding Proteins
  • Lamin Type A
  • Lamins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • Peptide Fragments
  • RNA-Binding Proteins
  • SYNE1 protein, human
  • Saccharomyces cerevisiae Proteins
  • Thymopoietins
  • Transcription Factors
  • emerin
  • nesprin-1alpha protein, human