Spectral tuning and evolution of primate short-wavelength-sensitive visual pigments
Spectral tuning and evolution of primate short-wavelength-sensitive visual pigments
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DOI：
10.1098/rspb.2011.0782
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发表时间：
2012-01-22
影响因子：
4.7
通讯作者：
Hunt, David M.
中科院分区：
文献类型：
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作者：
Carvalho, Livia S.;Davies, Wayne L.;Hunt, David M.
哺乳动物短波长敏感-1 （SWS1）色素的峰值灵敏度（λ (max)）范围从光谱的紫外（UV） （360-400 nm）到紫外（400-450 nm）区域。在大多数情况下，紫外线或紫色峰是由存在于位点86的残基决定的，其中Phe赋予紫外线灵敏度（UVS）， Ser、Tyr或Val引起向紫色波长的偏移。然而，在灵长类动物中，紫色敏感（VS）色素的调节机制似乎有所不同。在这项研究中，我们研究了原猴SWS1色素的调谐机制。其中一种，aye-aye，拥有一种具有Phe86的色素，但体外光谱分析显示是VS而不是uv色素。原猴体内86位的其他残基（Cys、Ser和Val）也给予VS色素。因此，86位点的替换并不是灵长类动物VS色素调节的主要机制，系统发育分析表明，86位点的替换在灵长类动物的进化中至少发生了5次。在所有灵长类动物的UV色素中，唯一保守的潜在调谐位点是Pro93，当它被Thr（在哺乳动物的UV色素中发现）取代时，aye-aye色素中的吸光度峰值在371 nm处移动到UV区域，λ（最大值）为371 nm。因此，我们得出结论，灵长类动物VS色素的调节取决于Pro93，而不是其他哺乳动物的Tyr86。然而，尚不确定在灵长类祖先中产生VS色素的初始事件是通过Thr93Pro还是Phe86Tyr替代实现的。
The peak sensitivities (lambda(max)) of the short-wavelength-sensitive-1 (SWS1) pigments in mammals range from the ultraviolet (UV) (360-400 nm) to the violet (400-450 nm) regions of the spectrum. In most cases, a UV or violet peak is determined by the residue present at site 86, with Phe conferring UV sensitivity (UVS) and either Ser, Tyr or Val causing a shift to violet wavelengths. In primates, however, the tuning mechanism of violet-sensitive (VS) pigments would appear to differ. In this study, we examine the tuning mechanisms of prosimian SWS1 pigments. One species, the aye-aye, possesses a pigment with Phe86 but in vitro spectral analysis reveals a VS rather than a UVS pigment. Other residues (Cys, Ser and Val) at site 86 in prosimians also gave VS pigments. Substitution at site 86 is not, therefore, the primary mechanism for the tuning of VS pigments in primates, and phylogenetic analysis indicates that substitutions at site 86 have occurred at least five times in primate evolution. The sole potential tuning site that is conserved in all primate VS pigments is Pro93, which when substituted by Thr (as found in mammalian UVS pigments) in the aye-aye pigment shifted the peak absorbance into the UV region with a lambda(max) value at 371 nm. We, therefore, conclude that the tuning of VS pigments in primates depends on Pro93, not Tyr86 as in other mammals. However, it remains uncertain whether the initial event that gave rise to the VS pigment in the ancestral primate was achieved by a Thr93Pro or a Phe86Tyr substitution.