Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2003 Nov 1;196(1):71-81.
doi: 10.1007/s00232-003-0626-y.

Downregulation of the Na(+)- D-glucose cotransporter SGLT1 by protein RS1 (RSC1A1) is dependent on dynamin and protein kinase C

M Veyhl  1 , C A Wagner, V Gorboulev, B M Schmitt, F Lang, H Koepsell
Affiliations
Comparative Study

Downregulation of the Na(+)- D-glucose cotransporter SGLT1 by protein RS1 (RSC1A1) is dependent on dynamin and protein kinase C

M Veyhl et al. J Membr Biol. .

Abstract

We have previously shown that the regulatory protein RS1, cloned from pig, rabbit and human (RSC1A1), is localized intracellularly and inhibits the transcription of the Na(+)- D-glucose cotransporter SGLT1 in LLC-PK(1) cells. We also reported that transport activities of human SGLT1 (hSGLT1) and human organic cation transporter hOCT2 expressed in Xenopus oocytes were decreased upon co-expression of human RS1 (hRS1). The present paper indicates that the glucose transporter GLUT1 and the peptide transporter PEPT1 are not influenced by hRS1. Voltage-clamp experiments in oocytes expressing hSGLT1 demonstrated that hRS1 reduced the maximal substrate-induced currents but did not change substrate activation, membrane potential dependence, Na(+) dependence or substrate selectivity of hSGLT1. Co-expression experiments with a dominant-negative dynamin mutant showed that the posttranslational inhibition of hSGLT1 by hRS1 was dependent on the function of dynamin. Finally, we observed that hRS1 changed the short-term effect of protein kinase C (PKC) on hSGLT1. Whereas the PKC activators phorbol-12-myristate-13-acetate (PMA) and sn-1,2-dioctanoyl glycerol (DOG) increased alpha-methyl glucose (AMG) uptake expressed by hSGLT1 alone as described earlier, PMA and DOG decreased AMG uptake mediated by hSGLT1 when hRS1 was co-expressed. Taken together, these data indicate that hRS1 modulates dynamin-dependent trafficking of intracellular vesicles containing hSGLT1 in Xenopus oocytes, and modulates PKC-dependent short-term regulation of this transporter.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Annu Rev Cell Dev Biol. 2000;16:483-519 - PubMed
    1. J Biol Chem. 1995 Mar 24;270(12):6456-63 - PubMed
    1. Am J Physiol. 1996 Jun;270(6 Pt 1):G919-26 - PubMed
    1. DNA Cell Biol. 1997 Jul;16(7):871-81 - PubMed
    1. Science. 1998 Jan 23;279(5350):573-7 - PubMed

Publication types

MeSH terms

LinkOut - more resources