Griscelli Syndrome Type 2 Sine Albinism: Unraveling Differential RAB27A Effector Engagement

Yuta Ohishi, Sandra Ammann, Vahid Ziaee, Katharina Strege, Miriam Groß, Carla Vazquez Amos, Mohammad Shahrooei, Parisa Ashournia, Anahita Razaghian, Gillian M. Griffiths, Stephan Ehl, Mitsunori Fukuda, Nima Parvaneh

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Griscelli syndrome type 2 (GS-2) is an inborn error of immunity characterized by partial albinism and episodes of hemophagocytic lymphohistiocytosis (HLH). It is caused by RAB27A mutations that encode RAB27A, a member of the Rab GTPase family. RAB27A is expressed in many tissues and regulates vesicular transport and organelle dynamics. Occasionally, GS-2 patients with RAB27A mutation display normal pigmentation. The study of such variants provides the opportunity to map distinct binding sites for tissue-specific effectors on RAB27A. Here we present a new case of GS-2 without albinism (GS-2 sine albinism) caused by a novel missense mutation (Val143Ala) in the RAB27A and characterize its functional cellular consequences. Using pertinent animal cell lines, the Val143Ala mutation impairs both the RAB27A–SLP2-A interaction and RAB27A–MUNC13-4 interaction, but it does not affect the RAB27A–melanophilin (MLPH)/SLAC2-A interaction that is crucial for skin and hair pigmentation. We conclude that disruption of the RAB27A–MUNC13-4 interaction in cytotoxic lymphocytes leads to the HLH predisposition of the GS-2 patient with the Val143Ala mutation. Finally, we include a review of GS-2 sine albinism cases reported in the literature, summarizing their genetic and clinical characteristics.

Original languageEnglish
Article number612977
JournalFrontiers in immunology
Volume11
DOIs
Publication statusPublished - 2020 Dec 10

Keywords

  • Griscelli syndrome type 2 sine albinism
  • MLPH/SLAC2-A
  • MUNC13-4
  • RAB27A
  • hemophagocytic lymphohistiocytosis
  • inborn error of immunity
  • whole-exome sequencing

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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