scholarly journals An Autosomal Dominant Cerebellar Ataxia Linked to Chromosome 16q22.1 Is Associated with a Single-Nucleotide Substitution in the 5′ Untranslated Region of the Gene Encoding a Protein with Spectrin Repeat and Rho Guanine-Nucleotide Exchange-Factor Domains

2005 ◽  
Vol 77 (2) ◽  
pp. 280-296 ◽  
Author(s):  
Kinya Ishikawa ◽  
Shuta Toru ◽  
Taiji Tsunemi ◽  
Mingshun Li ◽  
Kazuhiro Kobayashi ◽  
...  
Author(s):  
Chana Borjigin ◽  
Rhiannon K. Schilling ◽  
Jayakumar Bose ◽  
Maria Hrmova ◽  
Jiaen Qiu ◽  
...  

AbstractImproving salinity tolerance in the most widely cultivated cereal, bread wheat (Triticum aestivum L.), is essential to increase grain yields on saline agricultural lands. A Portuguese landrace, Mocho de Espiga Branca accumulates up to 6 folds greater leaf and sheath sodium (Na+) than two Australian cultivars, Gladius and Scout, under salt stress. Despite high leaf and sheath Na+ concentrations, Mocho de Espiga Branca maintained similar salinity tolerance compared to Gladius and Scout. A naturally occurring single nucleotide substitution was identified in the gene encoding a major Na+ transporter TaHKT1;5-D in Mocho de Espiga Branca, which resulted in a L190P amino acid residue variation. This variant prevents Mocho de Espiga Branca from retrieving Na+ from the root xylem leading to a high shoot Na+ concentration. The identification of the tissue tolerant Mocho de Espiga Branca will accelerate the development of more elite salt tolerant bread wheat cultivars.


2020 ◽  
Vol 6 (47) ◽  
pp. eabb7781
Author(s):  
Yuting Ke ◽  
Meiqian Weng ◽  
Gaurav Chhetri ◽  
Muhammad Usman ◽  
Yan Li ◽  
...  

Genetic mutations in the gene encoding transport protein particle complex 9 (trappc9), a subunit of TRAPP that acts as a guanine nucleotide exchange factor for rab proteins, cause intellectual disability with brain structural malformations by elusive mechanisms. Here, we report that trappc9-deficient mice exhibit a broad range of behavioral deficits and postnatal delay in growth of the brain. Contrary to volume decline of various brain structures, the striatum of trappc9 null mice was enlarged. An imbalance existed between dopamine D1 and D2 receptor containing neurons in the brain of trappc9-deficient mice; pharmacological manipulation of dopamine receptors improved performances of trappc9 null mice to levels of wild-type mice on cognitive tasks. Loss of trappc9 compromised the activation of rab11 in the brain and resulted in retardation of endocytic receptor recycling in neurons. Our study elicits a pathogenic mechanism and a potential treatment for trappc9-linked disorders including intellectual disability.


2003 ◽  
Vol 14 (3) ◽  
pp. 1109-1124 ◽  
Author(s):  
Michiko Nakamura-Kubo ◽  
Taro Nakamura ◽  
Aiko Hirata ◽  
Chikashi Shimoda

The Schizosaccharomyces pombe spo14-B221 mutant was originally isolated as a sporulation-deficient mutant. However, thespo14 + gene is essential for cell viability and growth. spo14 + is identical to the previously characterizedstl1 + gene encoding a putative homologue of Saccharomyces cerevisiae Sec12, which is essential for protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus. In the spo14 mutant cells, ER-like membranes were accumulated beneath the plasma membrane and the ER/Golgi shuttling protein Rer1 remained in the ER. Sec12 is a guanine nucleotide exchange factor for the Sar1 GTPase. Overproduction ofpsr1 + coding for an S. pombe Sar1 homologue suppressed both the sporulation defect ofspo14-B221 and cold-sensitive growth of newly isolatedspo14-6 and spo14-7 mutants. These results indicate that Spo14 is involved in early steps of the protein secretory pathway. The spo14-B221 allele carries a single nucleotide change in the branch point consensus of the fifth intron, which reduces the abundance of the spo14 mRNA. During meiosis II, the forespore membrane was initiated near spindle pole bodies; however, subsequent extension of the membrane was arrested before its closure into a sac. We conclude that Spo14 is responsible for the assembly of the forespore membrane by supplying membrane vesicles.


2021 ◽  
Vol 7 (12) ◽  
pp. 1037 ◽  
Author(s):  
Ignacio Bravo-Plaza ◽  
Miguel Hernández-González ◽  
Miguel Á. Peñalva

Contrary to the opinion recently offered by Dimou et al., our previously published biochemical, subcellular and genetic data supported our contention that AN11127 corresponds to the A. nidulans gene encoding Sec12, which is the guanine nucleotide exchange factor (GEF) specific for SAR1. We add here additional bioinformatics evidence that fully disprove the otherwise negative evidence reported by Dimou et al., highlighting the dangers associated with the lax interpretation of genomic data. On the positive side, we establish guidelines for the identification of this key secretory gene in other species of Ascomycota and Basidiomycota, including species of medical and applied interest.


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