Two human lysosomal membrane glycoproteins, h-lamp-1 and h-lamp-2, are encoded by genes localized to chromosome 13q34 and chromosome Xq24-25, respectively.
We have isolated previously cDNAs encoding two related human lysosomal membrane glycoproteins, h-lamp-1 and h-lamp-2 (Fukuda, M., Viitala, J., Matteson, J., and Carlsson, S.R. (1988) J. Biol. Chem. 263, 18920-18928). In the present study, we have determined the chromosomal localization of genes for h-lamp-1 and h-lamp-2. By using the method of in situ hybridization, we have localized the gene for h-lamp-1 to chromosome 13q34 and its related gene to chromosome 12p133. The hybridization of h-lamp-1 cDNA to chromosome 12p133 was observed even when probes representing different portions of h-lamp-1 cDNA were used. On ther other hand, the gene for h-lamp-2 were localized to Xq24-25 but no cross-hybridization to chromosome 12p133 was observed even though h-lamp-1 and h-lamp-2 are highly related. These results clearly indicate that human lamp-1 and lamp-2 are coded by separate genes on different chromosomes. The present results support our hypothesis that lamp-1 and lamp-2 diverged early in evolution and they have distinct functions which emerged as soon as eukaryotic cells acquired lysosomes as subcellular compartments.
Mattei
M G
MG
Institut National de la Santé et de la Recherche Medicale U.242/Centre de Genetique Medicale, Hopital d'Enfants de la Timone, Marseille, France.
Matterson
J
J
Chen
J W
JW
Williams
M A
MA
Fukuda
M
M
D015703:Antigens, CD; D002460:Cell Line; D002874:Chromosome Mapping; D002882:Chromosomes, Human, Pair 13; D015342:DNA Probes; D005260:Female; D015723:Gene Library; D005796:Genes; D006801:Humans; D051907:Lysosomal Membrane Proteins; D008247:Lysosomes / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D010920:Placenta / Q000378:metabolism; D010957:Plasmids; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D014960:X Chromosome
D015703:Antigens, CD; D015342:DNA Probes; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger