Identification and characterization of a second extracellular collagen-like protein made by group A Streptococcus:: Control of production at the level of translation
Identification and characterization of a second extracellular collagen-like protein made by group A Streptococcus:: Control of production at the level of translation
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DOI：
10.1128/iai.69.3.1729-1738.2001
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发表时间：
2001-03-01
影响因子：
3.1
通讯作者：
Musser, JM
中科院分区：
文献类型：
--
作者：
Lukomski, S;Nakashima, K;Musser, JM
最近的一项研究发现，A 组链球菌 (GAS) 表达与人类胶原蛋白相似的细胞表面蛋白（S, Lukomski, K. Nakashima, I. Abdi, V, J, Cipriano, R. M, Ireland, S. R, Reid, G, G, Adams, and J, M. Musser, Infect. Immun, 68:6542-6553, 2000），这 链球菌胶原蛋白样蛋白 (Scl) 包含一长段 Gly-X-X 基序区域，由血清型 M1 GAS 菌株产生。在本研究中，鉴定了 scl 基因家族的第二个成员，并将其命名为 scl2。 Scl2 蛋白还具有胶原蛋白样区域，在 M1 菌株中由 38 个连续的 Gly X-X 三联体基序组成。scl2 基因存在于所研究的所有 50 个遗传多样性 GAS 菌株中。 Scl2 蛋白具有高度多态性，所研究的 50 个菌株中 Gly-X-X 基序的数量从 M1 血清型菌株中的 31 个到 M28 和 M77 血清型分离株中的 79 个不等。 scl1和scl2基因在指数生长期同时转录，并产生Sd蛋白。 Scl1 和 Scl2 被鉴定为细胞相关形式，并且游离于培养物上清液中。Scl1 的产生受 Mga 的调节，Mga 是一种正转录调节因子，控制多种 GAS 毒力因子的表达。相反，Scl2 的产生在翻译水平上受到位于 GTG (Val) 起始密码子紧下游的短序列五核苷酸重复 (CAAAA) 数量的变化的控制。之前在 GAS 中尚未发现这种分子机制对蛋白质生产的控制。总之，数据表明 GAS 以受调控的方式同时产生两种细胞外人类胶原蛋白样蛋白。
A recent study found that group A Streptococcus (GAS) expresses a cell surface protein with similarity to human collagen (S, Lukomski, K. Nakashima, I. Abdi, V, J, Cipriano, R. M, Ireland, S. R, Reid, G, G, Adams, and J, M. Musser, Infect. Immun, 68:6542-6553, 2000), This streptococcal collagen-like protein (Scl) contains a long region of Gly-X-X motifs and was produced by serotype M1 GAS strains. In the present study, a second member of the scl gene family was identified and designated scl2. The Scl2 protein also has a collagen-like region, which in M1 strains is composed of 38 contiguous Gly X-X triplet motifs, The scl2 gene was present in all 50 genetically diverse GAS strains studied. The Scl2 protein is highly polymorphic, and the number of Gly-X-X motifs in the 50 strains studied ranged from 31 in one serotype M1 strain to 79 in serotype M28 and M77 isolates. The scl1 and scl2 genes were simultaneously transcribed in the exponential phase, and the Sd proteins were also produced. Scl1 and Scl2 were identified in a cell-associated form and free in culture supernatants, Production of Scl1 is regulated by Mga, a positive transcriptional regulator that controls expression of several GAS virulence factors. In contrast, production of Scl2 is controlled at the level of translation by variation in the number of short-sequence pentanucleotide repeats (CAAAA) located immediately downstream of the GTG (Val) start codon. Control of protein production by this molecular mechanism has not been identified previously in GAS. Together, the data indicate that GAS simultaneously produces two extracellular human collagen-like proteins in a regulated fashion.