Functional identification of the glycerol transport activity of Chlamydomonas reinhardtii CrMIP1.
By searching a Chlamydomonas expressed sequence tag database and by comparing the retrieved data with homologous sequences from a DNA database, we identified an expressed Chlamydomonas reinhardtii putative major intrinsic protein (MIP) gene. The nucleotide sequence, consisting of 1,631 bp, contains an open reading frame coding for a 300-amino-acid protein named CrMIP1. It possesses conserved NPA motifs, but is not highly homologous to known aquaporins. CrMIP1 was expressed in Saccharomyces cerevisiae and assayed for water and glycerol transport activity. By the stopped-flow spectrophotometric assay, CrMIP1 did not enhance the osmotic water permeability of membrane vesicles of the yeast transformant. However, the transformant cells showed glycerol transport activity in the in vivo assay using [14C]glycerol. This is the first report on the isolation and functional identification of a MIP member from algae.
Anderca
Marinela Ioana
MI
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601 Japan.
Suga
Shinobu
S
Furuichi
Takuya
T
Shimogawara
Kosuke
K
Maeshima
Masayoshi
M
Muto
Shoshi
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D017931:DNA Primers; D005990:Glycerol / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D005990:Glycerol