Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.1.32 (phosphoenolpyruvate carboxykinase)
 4,204 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mycobacterium sp. strain KMS was isolated from soils where remediation of polycyclic aromatic hydrocarbons was active. This isolate is a competent plant root colonizer through utilization of an array of carbon substrates available in the root exudates. Bioinformatic analyses based on the KMS genome propose pathways for C4- and C3-intermediate conversions during growth of the isolate on substrates requiring gluconeogenesis. Expression of candidate genes for these pathways was compared using semi-quantitative RT-PCR from cells grown on acetate, succinate, benzoate, or pyrene as sole carbon sources requiring gluconeogenesis during growth. Expression was examined for cells grown on fructose and mannitol, where gluconeogenesis would not be essential. Transcript accumulation in cells grown on all the carbon sources confirmed expression from genes involved in the glyoxylate shunt and a gene encoding a novel enzyme to complete the tricarboxylic acid cycle, a membrane-associated malate:quinone oxidoreductase (MQO). Transcript accumulations for genes encoding phosphoenolpyruvate carboxykinase, malic enzyme, and phosphoenolpyruvate synthase were weak for mannitol growth but were detected for the other carbon sources. Activities for PEP synthase and the membrane-associated MQO were confirmed in cell extracts at different levels indicating feasibility of their function in production of PEP for gluconeogenesis in this soil Mycobacterium.
 ...
PMID:The gluconeogenic pathway in a soil mycobacterium isolate with bioremediation ability. 2306 72

This paper addresses plasmodesmatal distribution and frequency in the leaf-blade bundles of four southern African grasses - one C3, and one each of the NAPD-malic-enzyme (ME), NAD-ME and phosphoenolpyruvate carboxykinase (PCK) C4 photosynthetic subtypes and, additionally, relates the calculated plasmodesmatal frequencies to the photosynthetic carbon-fixation rate. Plasmodesmata are, in all instances, constricted where they traverse suberin lamellae at the Kranz mesophyll-bundle sheath (KMS-BS), the bundle-sheath-vascular parenchyma (BS-VP), or the bundle-sheath-mestome-sheath interfaces (BS-MS). Frequency studies clearly show that plasmodesmata are most numerous at the KMS-BS, BS-MS and BS-VP interfaces, (31.9-76.8% of the total) and that their numbers decrease rapidly with increasing proximity to both thin- and thickwalled sieve tubes. In Themeda triandra var. imberbis (Retz.) A. Camus and Bromus unioloides H.B.K. thickwalled sieve tubes have few connections with vascular parenchyma cells and are, to all intents and purposes, almost totally isolated from the rest of the vascular tissue, indicating that the loading pathways for these sieve tubes are predominantly apoplastic. Although decreasing plasmodesmatal frequencies indicate that loading of assimilate may become progressively more apoplastic with increasing proximity to the sieve tubes, a symplastic route to the thin-walled sieve tubes cannot be ruled out. Studies of net assimilation rate indicate a good correlation of photosynthetic rate with the photosynthetic type (C3, C4 NADP-ME, C4 PCK, and C4 NAD-ME); furthermore, the lowest plasmodesmatal frequencies were associated with C3, and the highest with C4 NAD-ME types.
...
PMID:Plasmodesmatal distribution, structure and frequency in relation to assimilation in C3 and C 4 grasses in southern Africa. 2417 75