Tatsuhiko Tanaka
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Tatsuhiko Tanaka has a total of 18 co-authors. Here are the top co-authors by number of shared publications:
- Akie Kobayashi
Hirosaki University Graduate School of Medicine 1 Department of Pediatrics Hirosaki
1 shared publication - Akira Sugawara
Graduate School of Life Sciences, Tohoku University 2 Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences Sendai
1 shared publication - Erina Saito
Cell Biology and Histology, Hirosaki University Graduate School of Medicine 4 Department of Neuroanatomy Hirosaki
1 shared publication - Hirofumi Shibata
National Institute of Allergy and Infectious Diseases, National Institutes of Health 5 Cell Signaling and Immunity Section, Laboratory of Immune System Biology, Division of Intramural Research Bethesda, MD
1 shared publication - Hirokazu Kanegane
Department of Child Health and Development, Graduate School of Medical and Dental Sciences Institute of Science Tokyo Tokyo Japan
1 shared publication - Kentaro Haga
Graduate School of Life Sciences, Tohoku University 2 Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences Sendai
1 shared publication
Latest Publications
- Open Access
- 7 May 2026
- Published by Rockefeller University Press in Journal of Human Immunity
- Vol. 2 (4)
Functional characterization of Griscelli syndrome type 2 sine albinism in Japanese patients
Griscelli syndrome type 2 (GS2), caused by biallelic RAB27A variants, is classically associated with hypopigmentation and life-threatening hemophagocytic lymphohistiocytosis (HLH). However, a few patients exhibit normal pigmentation, termed GS2 sine albinism. We identified two unrelated Japanese patients with this presentation caused by compound heterozygous RAB27A variants, representing the first functionally characterized cases among Japanese patients. Functional studies were performed using RAB27A-null cell systems to evaluate the two allele pairs: p.Trp73Arg/p.Val143Ala (patient 1) and p.Ser106PhefsTer18/p.Ser115Arg (patient 2). The truncating allele p.Ser106PhefsTer18 and the missense allele p.Trp73Arg failed to restore peripheral melanosome distribution and lost binding to both melanophilin (MLPH) and MUNC13-4. In contrast, p.Val143Ala and p.Ser115Arg preserved MLPH interaction but showed reduced binding to MUNC13-4. These findings demonstrate that RAB27A variants can dissociate melanosome transport from immune effector function in an allele-dependent manner. Importantly, the absence of hypopigmentation does not exclude GS2. Combined genetic and functional analyses are essential for precise variant interpretation and for guiding timely curative intervention in GS2.
- 7 May 2026
- Published by Rockefeller University Press in Journal of Human Immunity
- Vol. 2 (4)
Open AccessFunctional characterization of Griscelli syndrome type 2 sine albinism in Japanese patients
Griscelli syndrome type 2 (GS2), caused by biallelic RAB27A variants, is classically associated with hypopigmentation and life-threatening hemophagocytic lymphohistiocytosis (HLH). However, a few patients exhibit normal pigmentation, termed GS2 sine albinism. We identified two unrelated Japanese patients with this presentation caused by compound heterozygous RAB27A variants, representing the first functionally characterized cases among Japanese patients. Functional studies were performed using RAB27A-null cell systems to evaluate the two allele pairs: p.Trp73Arg/p.Val143Ala (patient 1) and p.Ser106PhefsTer18/p.Ser115Arg (patient 2). The truncating allele p.Ser106PhefsTer18 and the missense allele p.Trp73Arg failed to restore peripheral melanosome distribution and lost binding to both melanophilin (MLPH) and MUNC13-4. In contrast, p.Val143Ala and p.Ser115Arg preserved MLPH interaction but showed reduced binding to MUNC13-4. These findings demonstrate that RAB27A variants can dissociate melanosome transport from immune effector function in an allele-dependent manner. Importantly, the absence of hypopigmentation does not exclude GS2. Combined genetic and functional analyses are essential for precise variant interpretation and for guiding timely curative intervention in GS2.