Distinct and redundant functions of mu1 medium chains of the AP-1 clathrin-associated protein complex in the nematode Caenorhabditis elegans

Mol Biol Cell. 2000 Aug;11(8):2743-56. doi: 10.1091/mbc.11.8.2743.

Abstract

In the nematode Caenorhabditis elegans, there exist two micro1 medium chains of the AP-1 clathrin-associated protein complex. Mutations of unc-101, the gene that encodes one of the micro1 chains, cause pleiotropic effects (). In this report, we identified and analyzed the second mu1 chain gene, apm-1. Unlike the mammalian homologs, the two medium chains are expressed ubiquitously throughout development. RNA interference (RNAi) experiments with apm-1 showed that apm-1 and unc-101 were redundant in embryogenesis and in vulval development. Consistent with this, a hybrid protein containing APM-1, when overexpressed, rescued the phenotype of an unc-101 mutant. However, single disruptions of apm-1 or unc-101 have distinct phenotypes, indicating that the two medium chains may have distinct functions. RNAi of any one of the small or large chains of AP-1 complex (sigma1, beta1, or gamma) showed a phenotype identical to that caused by the simultaneous disruption of unc-101 and apm-1, but not that by single disruption of either gene. This suggests that the two medium chains may share large and small chains in the AP-1 complexes. Thus, apm-1 and unc-101 encode two highly related micro1 chains that share redundant and distinct functions within AP-1 clathrin-associated protein complexes of the same tissue.

Publication types

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

MeSH terms

  • Adaptor Protein Complex 1*
  • Adaptor Protein Complex 2*
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Protein Complex mu Subunits*
  • Adaptor Protein Complex sigma Subunits*
  • Adaptor Proteins, Vesicular Transport
  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / drug effects
  • Caenorhabditis elegans / embryology
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins*
  • Clathrin / physiology*
  • Cloning, Molecular
  • Embryo, Nonmammalian / physiology
  • Evolution, Molecular
  • Female
  • Gene Expression Regulation, Developmental
  • Helminth Proteins / drug effects
  • Helminth Proteins / genetics
  • Helminth Proteins / physiology*
  • Larva / physiology
  • Membrane Proteins / drug effects
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Molecular Sequence Data
  • Mutation
  • Nerve Tissue Proteins / drug effects
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / physiology*
  • Nucleic Acid Synthesis Inhibitors / pharmacology
  • Phenotype
  • Phosphoproteins / drug effects
  • Phosphoproteins / genetics*
  • Phosphoproteins / physiology*
  • RNA, Double-Stranded / pharmacology
  • RNA, Helminth / biosynthesis
  • RNA, Helminth / drug effects
  • Recombinant Fusion Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Vulva / cytology
  • Vulva / embryology
  • Vulva / metabolism

Substances

  • Adaptor Protein Complex 1
  • Adaptor Protein Complex 2
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Protein Complex mu Subunits
  • Adaptor Protein Complex sigma Subunits
  • Adaptor Proteins, Vesicular Transport
  • Caenorhabditis elegans Proteins
  • Clathrin
  • Helminth Proteins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Nucleic Acid Synthesis Inhibitors
  • Phosphoproteins
  • RNA, Double-Stranded
  • RNA, Helminth
  • Recombinant Fusion Proteins
  • UNC-101 protein, C elegans
  • adaptor protein complex 1, mu 1 subunit
  • adaptor protein complex 1, sigma 1 subunit
  • adaptor protein complex 2, mu 1 subunit
  • apm-1 protein, C elegans