Rabbit Anti-Human TPK1 (a.a. 1-243) Polyclonal antibody

In the pathogen Candida albicans protein kinase A (PKA) catalytic subunit is encoded by two genes TPK1 and TPK2 and the regulatory subunit by one gene, BCY1. PKA mediates several cellular processes such as cell cycle regulation and the yeast to hyphae transition, a key factor for C albicans virulence. The catalytic isoforms Tpk1p and Tpk2p share redundant functions in vegetative growth and hyphal development, though they differentially regulate glycogen metabolism, the stress response pathway and pseudohyphal formation. In Saccharomyces cerevisiae it was earlier reported that BCY1 overexpression not only increased the amount of TPK3 mRNA but also its catalytic activity. In C. albicans a significant decrease in Bcy1p expression levels was already observed in tpk2 Delta null strains. In this work we showed that the upregulation in Bcy1p expression was observed in a set of strains having a TPK1 or TPK2 allele reintegrated in its own locus, as well as in strains expressing the TPKs under the control of the constitutive ACT1 promoter. To confirm the cross regulation event between Bcy1p and Tpkp expression we generated a mutant strain with the lowest PKA activity carrying one TPK1 and a unique BCY1 allele with the aim to obtain two derived strains in which BCY1 or TPK1 were placed under their own promoters inserted in the RPS10 neutral locus. We found that placing one copy of BCY1 upregulated the levels of Tpk1p and its catalytic activity: while TPK1 insertion led to an increase in BCY1 mRNA, Bcy1p and in a high cAMP binding activity. Our results suggest that C albicans cells were able to compensate for the increased levels of either Tpk1p or Tpk2p subunits with a corresponding elevation of Bcy1 protein levels and vice versa, implying a tightly regulated mechanism to balance holoenzyme formation. (C) 2011 Elsevier Inc. All rights reserved.

TPK deficiency, also known as thiamine metabolism dysfunction syndrome 5, is a rare autosomal recessive disorder of inborn error of metabolism caused by TPK1 gene mutation. Its clinical manifestation is highly variable, ranging from spontaneous remission to fatal metabolic crisis. Here, we describe two affected siblings in a Chinese family presenting with recurrent episodes of acute ataxia. Whole exome sequencing identified a homozygous missense variant c.382C > T (p.Leu128Phe) in the TPK gene, which is located in the thiamine binding domain and affects a highly conserved amino acid. Besides, a review of the 18 previously reported patients provides a better understanding of the clinical and genetic features of this disorder. TPK deficiency may be an under-diagnosed cause of acute encephalopathy and ataxia. Given the potential benefit of early intervention, TPK deficiency should be considered in patients with episodic encephalopathy or ataxia, especially those associated with lactic acidosis and alpha-ketoglutaric aciduria. Significant decreased TPP in the blood is a strong hint of the disease. WES (whole exome sequencing) can help to further identify the molecular diagnosis.