Gough N R, Hatem C L, Fambrough D M
Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
DNA Cell Biol. 1995 Oct;14(10):863-7. doi: 10.1089/dna.1995.14.863.
The two lysosome-associated membrane proteins, LAMP-1 and LAMP-2, are major integral membrane proteins of the lysosomes. They also occur in the plasma membrane, where they have been discovered independently as principal lactosaminoglycan-bearing glycoproteins and as tumor antigens. Avian LAMP-2 has recently been shown to be encoded by at least three transcripts resulting in variant transmembrane and cytoplasmic domains (Hatem et al., 1995). We report isolation and characterization of chicken genomic clones indicating that the three transcripts are the result of alternative splicing of a single LAMP-2 gene. Only a single LAMP-2, homologous to chicken LAMP-2a, has been described in mammals. To ascertain whether multiple forms of LAMP-2 also occur in mammals, we cloned cDNAs encoding LAMP-2 variants homologous to avian LAMP-2b and LAMP-2c from mouse brain cDNA libraries. Thus, the family of LAMP-2 proteins is conserved from bird to mammals and the diversity is generated by alternative splicing of a single LAMP-2 gene.
两种溶酶体相关膜蛋白，即LAMP - 1和LAMP - 2，是溶酶体的主要整合膜蛋白。它们也存在于质膜中，在质膜中它们分别作为主要的携带乳糖胺聚糖的糖蛋白和肿瘤抗原被独立发现。最近发现禽源LAMP - 2由至少三种转录本编码，这些转录本产生不同的跨膜结构域和胞质结构域（Hatem等人，1995年）。我们报道了鸡基因组克隆的分离和鉴定，表明这三种转录本是单个LAMP - 2基因可变剪接的结果。在哺乳动物中仅描述了一种与鸡LAMP - 2a同源的LAMP - 2。为了确定LAMP - 2的多种形式是否也存在于哺乳动物中，我们从小鼠脑cDNA文库中克隆了与禽源LAMP - 2b和LAMP - 2c同源的编码LAMP - 2变体的cDNA。因此，LAMP - 2蛋白家族在从鸟类到哺乳动物中是保守的，并且其多样性是由单个LAMP - 2基因的可变剪接产生的。
