The Saccharomyces cerevisiae genome contains three genes encoding alkali metal cation/H+ antiporters (Nha1p, Nhx1p, Kha1p) that differ in cell localization, substrate specificity and physiological function. Systematic genome sequencing of other yeast species revealed highly conserved homologous ORFs in all of them. We compared the yeast sequences both at DNA and protein levels. The subfamily of yeast endosomal/prevacuolar Nhx1 antiporters is closely related to mammalian plasma membrane NHE proteins and to both plasma membrane and vacuolar plant antiporters. The high sequence conservation within this subfamily of yeast antiporters suggests that Nhx1p is of great importance in cell physiology. Yeast Kha1 proteins probably belong to the same subfamily as bacterial antiporters, whereas Nhal proteins form a distinct subfamily.

• MeSH
• DNA fungální analýza   MeSH
• draslíko-vodíkové antiportéry chemie   klasifikace   genetika   MeSH
• fylogeneze MeSH
• membránové proteiny chemie   klasifikace   genetika   MeSH
• molekulární sekvence - údaje MeSH
• Na(+)-H(+) antiport chemie   klasifikace   genetika   MeSH
• proteiny přenášející kationty chemie   klasifikace   genetika   MeSH
• Saccharomyces cerevisiae - proteiny chemie   klasifikace   genetika   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza DNA MeSH
• sekvenční homologie aminokyselin MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA fungální MeSH
• draslíko-vodíkové antiportéry MeSH
• KHA1 protein, S cerevisiae MeSH Prohlížeč
• membránové proteiny MeSH
• Na(+)-H(+) antiport MeSH
• NHA1 protein, S cerevisiae MeSH Prohlížeč
• NHX1 protein, S cerevisiae MeSH Prohlížeč
• proteiny přenášející kationty MeSH
• Saccharomyces cerevisiae - proteiny MeSH

An amiloride-resistant mutant with diminished Na+/H+ antiporter activity was isolated from Methanothermobacter thermoautotrophicus. To define the protein basis of amiloride resistance, the composition of membrane-associated proteins was partially characterized and compared with that of the wild type strain. An abundant 670-kDa membrane-associated protein that was present only in the mutant strain was analyzed by MALDI-TOF MS and identified as a coenzyme F420-reducing hydrogenase. The amiloride resistance was not accompanied by changes in protein size or changes in the level of subunits A or B of the A1A0-type ATP synthase; on the other hand, the SDS-PAGE patterns of the chloroform-methanol extract of membranes from both strains were different. Two bands with calculated molecular mass 16 and 11 kDa were identified as MtrD and AtpK, respectively. The observed over-expression of a 22.7-kDa protein in the mutant cells may represent the multimeric form of the MtrD subunit. These results show that the impairment of the Na+/H+ antiporter system in the amiloride-resistant mutant of Methanothermobacter thermoautotrophicus is accompanied by only small changes in a few membrane-associated proteins.

• MeSH
• amilorid farmakologie   MeSH
• bakteriální léková rezistence účinky léků   genetika   fyziologie   MeSH
• bakteriální proteiny chemie   účinky léků   MeSH
• blokátory sodíkových kanálů farmakologie   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• membránové proteiny chemie   účinky léků   genetika   MeSH
• Methanobacteriaceae účinky léků   genetika   fyziologie   MeSH
• mutantní proteiny chemie   účinky léků   MeSH
• Na(+)-H(+) antiport chemie   účinky léků   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• amilorid MeSH
• bakteriální proteiny MeSH
• blokátory sodíkových kanálů MeSH
• membránové proteiny MeSH
• mutantní proteiny MeSH
• Na(+)-H(+) antiport MeSH