Mammalian Glutaminase Gls2 Gene Encodes Two Functional Alternative Transcripts by a Surrogate Promoter Usage Mechanism

Glutaminase is expressed in most mammalian tissues and cancer cells, but the regulation of its expression is poorly understood. An essential step to accomplish this goal is the characterization of its species- and cell-specific isoenzyme pattern of expression. Our aim was to identify and characterize transcript variants of the mammalian glutaminase Gls2 gene.We demonstrate for the first time simultaneous expression of two transcript variants from the Gls2 gene in human, rat and mouse. A combination of RT-PCR, primer-extension analysis, bioinformatics, real-time PCR, in vitro transcription and translation and immunoblot analysis was applied to investigate GLS2 transcripts in mammalian tissues. Short (LGA) and long (GAB) transcript forms were isolated in brain and liver tissue of human, rat and mouse. The short LGA transcript arises by a combination of two mechanisms of transcriptional modulation: alternative transcription initiation and alternative promoter. The LGA variant contains both the transcription start site (TSS) and the alternative promoter in the first intron of the Gls2 gene. The full human LGA transcript has two in-frame ATGs in the first exon, which are missing in orthologous rat and mouse transcripts. In vitro transcription and translation of human LGA yielded two polypeptides of the predicted size, but only the canonical full-length protein displayed catalytic activity. Relative abundance of GAB and LGA transcripts showed marked variations depending on species and tissues analyzed.This is the first report demonstrating expression of alternative transcripts of the mammalian Gls2 gene. Transcriptional mechanisms giving rise to GLS2 variants and isolation of novel GLS2 transcripts in human, rat and mouse are presented. Results were also confirmed at the protein level, where catalytic activity was demonstrated for the human LGA protein. Relative abundance of GAB and LGA transcripts was species- and tissue-specific providing evidence of a differential regulation of GLS2 transcripts in mammals

Hair's molecular structure and development [Estructura molecular y desarrollo del pelo]

The aim of the present article is to review the hair's anatomy, histology, embriology, growth, and development Also, we discuss molecular biology basic aspects and the molecular mechanisms regulating the hair's morphogenesis and development Currently, it is necessary to know about the hair's anatomy and molecular structure in order to design new treatments for alopecias. Hair loss affects most of the world population

Symmetrical hyperkeratotic and hyperpigmented plaques associated with palmoplantar keratoderma

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Hair's molecular structure and development [Estructura molecular y desarrollo del pelo]

The aim of the present article is to review the hair's anatomy, histology, embriology, growth, and development Also, we discuss molecular biology basic aspects and the molecular mechanisms regulating the hair's morphogenesis and development Currently, it is necessary to know about the hair's anatomy and molecular structure in order to design new treatments for alopecias. Hair loss affects most of the world population